libcxx initial import

llvm-svn: 103490

9 files changed, 2654 insertions, 0 deletions

diff --git a/libcxx/test/strings/basic.string/string.modifiers/string::insert/iter_char.pass.cpp b/libcxx/test/strings/basic.string/string.modifiers/string::insert/iter_char.pass.cpp
new file mode 100644
index 00000000000..358d40e1dc0
--- /dev/null
+++ b/libcxx/test/strings/basic.string/string.modifiers/string::insert/iter_char.pass.cpp
@@ -0,0 +1,51 @@
+//===----------------------------------------------------------------------===//
+//
+// ΚΚΚΚΚΚΚΚΚΚΚΚΚΚΚΚΚΚΚΚThe LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// <string>
+
+// iterator insert(const_iterator p, charT c);
+
+#include <string>
+#include <stdexcept>
+#include <cassert>
+
+template <class S>
+void
+test(S& s, typename S::const_iterator p, typename S::value_type c, S expected)
+{
+    bool sufficient_cap = s.size() < s.capacity();
+    typename S::difference_type pos = p - s.begin();
+    typename S::iterator i = s.insert(p, c);
+    assert(s.__invariants());
+    assert(s == expected);
+    assert(i - s.begin() == pos);
+    assert(*i == c);
+    if (sufficient_cap)
+        assert(i == p);
+}
+
+int main()
+{
+    typedef std::string S;
+    S s;
+    test(s, s.begin(), '1', S("1"));
+    test(s, s.begin(), 'a', S("a1"));
+    test(s, s.end(), 'b', S("a1b"));
+    test(s, s.end()-1, 'c', S("a1cb"));
+    test(s, s.end()-2, 'd', S("a1dcb"));
+    test(s, s.end()-3, '2', S("a12dcb"));
+    test(s, s.end()-4, '3', S("a132dcb"));
+    test(s, s.end()-5, '4', S("a1432dcb"));
+    test(s, s.begin()+1, '5', S("a51432dcb"));
+    test(s, s.begin()+2, '6', S("a561432dcb"));
+    test(s, s.begin()+3, '7', S("a5671432dcb"));
+    test(s, s.begin()+4, 'A', S("a567A1432dcb"));
+    test(s, s.begin()+5, 'B', S("a567AB1432dcb"));
+    test(s, s.begin()+6, 'C', S("a567ABC1432dcb"));
+}
diff --git a/libcxx/test/strings/basic.string/string.modifiers/string::insert/iter_initializer_list.pass.cpp b/libcxx/test/strings/basic.string/string.modifiers/string::insert/iter_initializer_list.pass.cpp
new file mode 100644
index 00000000000..ad95511af6a
--- /dev/null
+++ b/libcxx/test/strings/basic.string/string.modifiers/string::insert/iter_initializer_list.pass.cpp
@@ -0,0 +1,27 @@
+//===----------------------------------------------------------------------===//
+//
+// ΚΚΚΚΚΚΚΚΚΚΚΚΚΚΚΚΚΚΚΚThe LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// <string>
+
+// iterator insert(const_iterator p, initializer_list<charT> il);
+
+#include <string>
+#include <cassert>
+
+int main()
+{
+#ifdef _LIBCPP_MOVE
+    {
+        std::string s("123456");
+        std::string::iterator i = s.insert(s.begin() + 3, {'a', 'b', 'c'});
+        assert(i - s.begin() == 3);
+        assert(s == "123abc456");
+    }
+#endif
+}
diff --git a/libcxx/test/strings/basic.string/string.modifiers/string::insert/iter_iter_iter.pass.cpp b/libcxx/test/strings/basic.string/string.modifiers/string::insert/iter_iter_iter.pass.cpp
new file mode 100644
index 00000000000..87304c6817d
--- /dev/null
+++ b/libcxx/test/strings/basic.string/string.modifiers/string::insert/iter_iter_iter.pass.cpp
@@ -0,0 +1,76 @@
+//===----------------------------------------------------------------------===//
+//
+// ΚΚΚΚΚΚΚΚΚΚΚΚΚΚΚΚΚΚΚΚThe LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// <string>
+
+// template<class InputIterator> 
+//   iterator insert(const_iterator p, InputIterator first, InputIterator last);
+
+#include <string>
+#include <cassert>
+
+#include "../../input_iterator.h"
+
+template <class S, class It>
+void
+test(S s, typename S::difference_type pos, It first, It last, S expected)
+{
+    typename S::const_iterator p = s.cbegin() + pos;
+    typename S::iterator i = s.insert(p, first, last);
+    assert(s.__invariants());
+    assert(i - s.begin() == pos);
+    assert(s == expected);
+}
+
+int main()
+{
+    typedef std::string S;
+    const char* s = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
+    test(S(), 0, s, s, S());
+    test(S(), 0, s, s+1, S("A"));
+    test(S(), 0, s, s+10, S("ABCDEFGHIJ"));
+    test(S(), 0, s, s+52, S("ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"));
+
+    test(S("12345"), 0, s, s, S("12345"));
+    test(S("12345"), 1, s, s+1, S("1A2345"));
+    test(S("12345"), 4, s, s+10, S("1234ABCDEFGHIJ5"));
+    test(S("12345"), 5, s, s+52, S("12345ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"));
+
+    test(S("1234567890"), 0, s, s, S("1234567890"));
+    test(S("1234567890"), 1, s, s+1, S("1A234567890"));
+    test(S("1234567890"), 10, s, s+10, S("1234567890ABCDEFGHIJ"));
+    test(S("1234567890"), 8, s, s+52, S("12345678ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz90"));
+
+    test(S("12345678901234567890"), 3, s, s, S("12345678901234567890"));
+    test(S("12345678901234567890"), 3, s, s+1, S("123A45678901234567890"));
+    test(S("12345678901234567890"), 15, s, s+10, S("123456789012345ABCDEFGHIJ67890"));
+    test(S("12345678901234567890"), 20, s, s+52,
+         S("12345678901234567890ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"));
+
+    test(S(), 0, input_iterator<const char*>(s), input_iterator<const char*>(s), S());
+    test(S(), 0, input_iterator<const char*>(s), input_iterator<const char*>(s+1), S("A"));
+    test(S(), 0, input_iterator<const char*>(s), input_iterator<const char*>(s+10), S("ABCDEFGHIJ"));
+    test(S(), 0, input_iterator<const char*>(s), input_iterator<const char*>(s+52), S("ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"));
+
+    test(S("12345"), 0, input_iterator<const char*>(s), input_iterator<const char*>(s), S("12345"));
+    test(S("12345"), 1, input_iterator<const char*>(s), input_iterator<const char*>(s+1), S("1A2345"));
+    test(S("12345"), 4, input_iterator<const char*>(s), input_iterator<const char*>(s+10), S("1234ABCDEFGHIJ5"));
+    test(S("12345"), 5, input_iterator<const char*>(s), input_iterator<const char*>(s+52), S("12345ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"));
+
+    test(S("1234567890"), 0, input_iterator<const char*>(s), input_iterator<const char*>(s), S("1234567890"));
+    test(S("1234567890"), 1, input_iterator<const char*>(s), input_iterator<const char*>(s+1), S("1A234567890"));
+    test(S("1234567890"), 10, input_iterator<const char*>(s), input_iterator<const char*>(s+10), S("1234567890ABCDEFGHIJ"));
+    test(S("1234567890"), 8, input_iterator<const char*>(s), input_iterator<const char*>(s+52), S("12345678ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz90"));
+
+    test(S("12345678901234567890"), 3, input_iterator<const char*>(s), input_iterator<const char*>(s), S("12345678901234567890"));
+    test(S("12345678901234567890"), 3, input_iterator<const char*>(s), input_iterator<const char*>(s+1), S("123A45678901234567890"));
+    test(S("12345678901234567890"), 15, input_iterator<const char*>(s), input_iterator<const char*>(s+10), S("123456789012345ABCDEFGHIJ67890"));
+    test(S("12345678901234567890"), 20, input_iterator<const char*>(s), input_iterator<const char*>(s+52),
+         S("12345678901234567890ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"));
+}
diff --git a/libcxx/test/strings/basic.string/string.modifiers/string::insert/iter_size_char.pass.cpp b/libcxx/test/strings/basic.string/string.modifiers/string::insert/iter_size_char.pass.cpp
new file mode 100644
index 00000000000..89d6e5ce1ae
--- /dev/null
+++ b/libcxx/test/strings/basic.string/string.modifiers/string::insert/iter_size_char.pass.cpp
@@ -0,0 +1,96 @@
+//===----------------------------------------------------------------------===//
+//
+// ΚΚΚΚΚΚΚΚΚΚΚΚΚΚΚΚΚΚΚΚThe LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// <string>
+
+// iterator insert(const_iterator p, size_type n, charT c);
+
+#include <string>
+#include <cassert>
+
+template <class S>
+void
+test(S s, typename S::difference_type pos, typename S::size_type n,
+     typename S::value_type c, S expected)
+{
+    typename S::const_iterator p = s.cbegin() + pos;
+    typename S::iterator i = s.insert(p, n, c);
+    assert(s.__invariants());
+    assert(i - s.begin() == pos);
+    assert(s == expected);
+}
+
+int main()
+{
+    typedef std::string S;
+    test(S(""), 0, 0, '1', S(""));
+    test(S(""), 0, 5, '1', S("11111"));
+    test(S(""), 0, 10, '1', S("1111111111"));
+    test(S(""), 0, 20, '1', S("11111111111111111111"));
+    test(S("abcde"), 0, 0, '1', S("abcde"));
+    test(S("abcde"), 0, 5, '1', S("11111abcde"));
+    test(S("abcde"), 0, 10, '1', S("1111111111abcde"));
+    test(S("abcde"), 0, 20, '1', S("11111111111111111111abcde"));
+    test(S("abcde"), 1, 0, '1', S("abcde"));
+    test(S("abcde"), 1, 5, '1', S("a11111bcde"));
+    test(S("abcde"), 1, 10, '1', S("a1111111111bcde"));
+    test(S("abcde"), 1, 20, '1', S("a11111111111111111111bcde"));
+    test(S("abcde"), 2, 0, '1', S("abcde"));
+    test(S("abcde"), 2, 5, '1', S("ab11111cde"));
+    test(S("abcde"), 2, 10, '1', S("ab1111111111cde"));
+    test(S("abcde"), 2, 20, '1', S("ab11111111111111111111cde"));
+    test(S("abcde"), 4, 0, '1', S("abcde"));
+    test(S("abcde"), 4, 5, '1', S("abcd11111e"));
+    test(S("abcde"), 4, 10, '1', S("abcd1111111111e"));
+    test(S("abcde"), 4, 20, '1', S("abcd11111111111111111111e"));
+    test(S("abcde"), 5, 0, '1', S("abcde"));
+    test(S("abcde"), 5, 5, '1', S("abcde11111"));
+    test(S("abcde"), 5, 10, '1', S("abcde1111111111"));
+    test(S("abcde"), 5, 20, '1', S("abcde11111111111111111111"));
+    test(S("abcdefghij"), 0, 0, '1', S("abcdefghij"));
+    test(S("abcdefghij"), 0, 5, '1', S("11111abcdefghij"));
+    test(S("abcdefghij"), 0, 10, '1', S("1111111111abcdefghij"));
+    test(S("abcdefghij"), 0, 20, '1', S("11111111111111111111abcdefghij"));
+    test(S("abcdefghij"), 1, 0, '1', S("abcdefghij"));
+    test(S("abcdefghij"), 1, 5, '1', S("a11111bcdefghij"));
+    test(S("abcdefghij"), 1, 10, '1', S("a1111111111bcdefghij"));
+    test(S("abcdefghij"), 1, 20, '1', S("a11111111111111111111bcdefghij"));
+    test(S("abcdefghij"), 5, 0, '1', S("abcdefghij"));
+    test(S("abcdefghij"), 5, 5, '1', S("abcde11111fghij"));
+    test(S("abcdefghij"), 5, 10, '1', S("abcde1111111111fghij"));
+    test(S("abcdefghij"), 5, 20, '1', S("abcde11111111111111111111fghij"));
+    test(S("abcdefghij"), 9, 0, '1', S("abcdefghij"));
+    test(S("abcdefghij"), 9, 5, '1', S("abcdefghi11111j"));
+    test(S("abcdefghij"), 9, 10, '1', S("abcdefghi1111111111j"));
+    test(S("abcdefghij"), 9, 20, '1', S("abcdefghi11111111111111111111j"));
+    test(S("abcdefghij"), 10, 0, '1', S("abcdefghij"));
+    test(S("abcdefghij"), 10, 5, '1', S("abcdefghij11111"));
+    test(S("abcdefghij"), 10, 10, '1', S("abcdefghij1111111111"));
+    test(S("abcdefghij"), 10, 20, '1', S("abcdefghij11111111111111111111"));
+    test(S("abcdefghijklmnopqrst"), 0, 0, '1', S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 5, '1', S("11111abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 10, '1', S("1111111111abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 20, '1', S("11111111111111111111abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 0, '1', S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 5, '1', S("a11111bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 10, '1', S("a1111111111bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 20, '1', S("a11111111111111111111bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 0, '1', S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 5, '1', S("abcdefghij11111klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 10, '1', S("abcdefghij1111111111klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 20, '1', S("abcdefghij11111111111111111111klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 19, 0, '1', S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 19, 5, '1', S("abcdefghijklmnopqrs11111t"));
+    test(S("abcdefghijklmnopqrst"), 19, 10, '1', S("abcdefghijklmnopqrs1111111111t"));
+    test(S("abcdefghijklmnopqrst"), 19, 20, '1', S("abcdefghijklmnopqrs11111111111111111111t"));
+    test(S("abcdefghijklmnopqrst"), 20, 0, '1', S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 20, 5, '1', S("abcdefghijklmnopqrst11111"));
+    test(S("abcdefghijklmnopqrst"), 20, 10, '1', S("abcdefghijklmnopqrst1111111111"));
+    test(S("abcdefghijklmnopqrst"), 20, 20, '1', S("abcdefghijklmnopqrst11111111111111111111"));
+}
diff --git a/libcxx/test/strings/basic.string/string.modifiers/string::insert/size_pointer.pass.cpp b/libcxx/test/strings/basic.string/string.modifiers/string::insert/size_pointer.pass.cpp
new file mode 100644
index 00000000000..a36e42ea1b6
--- /dev/null
+++ b/libcxx/test/strings/basic.string/string.modifiers/string::insert/size_pointer.pass.cpp
@@ -0,0 +1,122 @@
+//===----------------------------------------------------------------------===//
+//
+// ΚΚΚΚΚΚΚΚΚΚΚΚΚΚΚΚΚΚΚΚThe LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// <string>
+
+// basic_string<charT,traits,Allocator>& 
+//   insert(size_type pos, const charT* s);
+
+#include <string>
+#include <stdexcept>
+#include <cassert>
+
+template <class S>
+void
+test(S s, typename S::size_type pos, const typename S::value_type* str, S expected)
+{
+    typename S::size_type old_size = s.size();
+    S s0 = s;
+    try
+    {
+        s.insert(pos, str);
+        assert(s.__invariants());
+        assert(pos <= old_size);
+        assert(s == expected);
+    }
+    catch (std::out_of_range&)
+    {
+        assert(pos > old_size);
+        assert(s == s0);
+    }
+}
+
+int main()
+{
+    typedef std::string S;
+    test(S(""), 0, "", S(""));
+    test(S(""), 0, "12345", S("12345"));
+    test(S(""), 0, "1234567890", S("1234567890"));
+    test(S(""), 0, "12345678901234567890", S("12345678901234567890"));
+    test(S(""), 1, "", S("can't happen"));
+    test(S(""), 1, "12345", S("can't happen"));
+    test(S(""), 1, "1234567890", S("can't happen"));
+    test(S(""), 1, "12345678901234567890", S("can't happen"));
+    test(S("abcde"), 0, "", S("abcde"));
+    test(S("abcde"), 0, "12345", S("12345abcde"));
+    test(S("abcde"), 0, "1234567890", S("1234567890abcde"));
+    test(S("abcde"), 0, "12345678901234567890", S("12345678901234567890abcde"));
+    test(S("abcde"), 1, "", S("abcde"));
+    test(S("abcde"), 1, "12345", S("a12345bcde"));
+    test(S("abcde"), 1, "1234567890", S("a1234567890bcde"));
+    test(S("abcde"), 1, "12345678901234567890", S("a12345678901234567890bcde"));
+    test(S("abcde"), 2, "", S("abcde"));
+    test(S("abcde"), 2, "12345", S("ab12345cde"));
+    test(S("abcde"), 2, "1234567890", S("ab1234567890cde"));
+    test(S("abcde"), 2, "12345678901234567890", S("ab12345678901234567890cde"));
+    test(S("abcde"), 4, "", S("abcde"));
+    test(S("abcde"), 4, "12345", S("abcd12345e"));
+    test(S("abcde"), 4, "1234567890", S("abcd1234567890e"));
+    test(S("abcde"), 4, "12345678901234567890", S("abcd12345678901234567890e"));
+    test(S("abcde"), 5, "", S("abcde"));
+    test(S("abcde"), 5, "12345", S("abcde12345"));
+    test(S("abcde"), 5, "1234567890", S("abcde1234567890"));
+    test(S("abcde"), 5, "12345678901234567890", S("abcde12345678901234567890"));
+    test(S("abcde"), 6, "", S("can't happen"));
+    test(S("abcde"), 6, "12345", S("can't happen"));
+    test(S("abcde"), 6, "1234567890", S("can't happen"));
+    test(S("abcde"), 6, "12345678901234567890", S("can't happen"));
+    test(S("abcdefghij"), 0, "", S("abcdefghij"));
+    test(S("abcdefghij"), 0, "12345", S("12345abcdefghij"));
+    test(S("abcdefghij"), 0, "1234567890", S("1234567890abcdefghij"));
+    test(S("abcdefghij"), 0, "12345678901234567890", S("12345678901234567890abcdefghij"));
+    test(S("abcdefghij"), 1, "", S("abcdefghij"));
+    test(S("abcdefghij"), 1, "12345", S("a12345bcdefghij"));
+    test(S("abcdefghij"), 1, "1234567890", S("a1234567890bcdefghij"));
+    test(S("abcdefghij"), 1, "12345678901234567890", S("a12345678901234567890bcdefghij"));
+    test(S("abcdefghij"), 5, "", S("abcdefghij"));
+    test(S("abcdefghij"), 5, "12345", S("abcde12345fghij"));
+    test(S("abcdefghij"), 5, "1234567890", S("abcde1234567890fghij"));
+    test(S("abcdefghij"), 5, "12345678901234567890", S("abcde12345678901234567890fghij"));
+    test(S("abcdefghij"), 9, "", S("abcdefghij"));
+    test(S("abcdefghij"), 9, "12345", S("abcdefghi12345j"));
+    test(S("abcdefghij"), 9, "1234567890", S("abcdefghi1234567890j"));
+    test(S("abcdefghij"), 9, "12345678901234567890", S("abcdefghi12345678901234567890j"));
+    test(S("abcdefghij"), 10, "", S("abcdefghij"));
+    test(S("abcdefghij"), 10, "12345", S("abcdefghij12345"));
+    test(S("abcdefghij"), 10, "1234567890", S("abcdefghij1234567890"));
+    test(S("abcdefghij"), 10, "12345678901234567890", S("abcdefghij12345678901234567890"));
+    test(S("abcdefghij"), 11, "", S("can't happen"));
+    test(S("abcdefghij"), 11, "12345", S("can't happen"));
+    test(S("abcdefghij"), 11, "1234567890", S("can't happen"));
+    test(S("abcdefghij"), 11, "12345678901234567890", S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 0, "", S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, "12345", S("12345abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, "1234567890", S("1234567890abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, "12345678901234567890", S("12345678901234567890abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, "", S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, "12345", S("a12345bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, "1234567890", S("a1234567890bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, "12345678901234567890", S("a12345678901234567890bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, "", S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, "12345", S("abcdefghij12345klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, "1234567890", S("abcdefghij1234567890klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, "12345678901234567890", S("abcdefghij12345678901234567890klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 19, "", S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 19, "12345", S("abcdefghijklmnopqrs12345t"));
+    test(S("abcdefghijklmnopqrst"), 19, "1234567890", S("abcdefghijklmnopqrs1234567890t"));
+    test(S("abcdefghijklmnopqrst"), 19, "12345678901234567890", S("abcdefghijklmnopqrs12345678901234567890t"));
+    test(S("abcdefghijklmnopqrst"), 20, "", S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 20, "12345", S("abcdefghijklmnopqrst12345"));
+    test(S("abcdefghijklmnopqrst"), 20, "1234567890", S("abcdefghijklmnopqrst1234567890"));
+    test(S("abcdefghijklmnopqrst"), 20, "12345678901234567890", S("abcdefghijklmnopqrst12345678901234567890"));
+    test(S("abcdefghijklmnopqrst"), 21, "", S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, "12345", S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, "1234567890", S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, "12345678901234567890", S("can't happen"));
+}
diff --git a/libcxx/test/strings/basic.string/string.modifiers/string::insert/size_pointer_size.pass.cpp b/libcxx/test/strings/basic.string/string.modifiers/string::insert/size_pointer_size.pass.cpp
new file mode 100644
index 00000000000..40460c0ad1f
--- /dev/null
+++ b/libcxx/test/strings/basic.string/string.modifiers/string::insert/size_pointer_size.pass.cpp
@@ -0,0 +1,363 @@
+//===----------------------------------------------------------------------===//
+//
+// ΚΚΚΚΚΚΚΚΚΚΚΚΚΚΚΚΚΚΚΚThe LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// <string>
+
+// basic_string<charT,traits,Allocator>& 
+//   insert(size_type pos, const charT* s, size_type n);
+
+#include <string>
+#include <stdexcept>
+#include <cassert>
+
+template <class S>
+void
+test(S s, typename S::size_type pos, const typename S::value_type* str,
+     typename S::size_type n, S expected)
+{
+    typename S::size_type old_size = s.size();
+    S s0 = s;
+    try
+    {
+        s.insert(pos, str, n);
+        assert(s.__invariants());
+        assert(pos <= old_size);
+        assert(s == expected);
+    }
+    catch (std::out_of_range&)
+    {
+        assert(pos > old_size);
+        assert(s == s0);
+    }
+}
+
+int main()
+{
+    typedef std::string S;
+    test(S(""), 0, "", 0, S(""));
+    test(S(""), 0, "12345", 0, S(""));
+    test(S(""), 0, "12345", 1, S("1"));
+    test(S(""), 0, "12345", 2, S("12"));
+    test(S(""), 0, "12345", 4, S("1234"));
+    test(S(""), 0, "12345", 5, S("12345"));
+    test(S(""), 0, "1234567890", 0, S(""));
+    test(S(""), 0, "1234567890", 1, S("1"));
+    test(S(""), 0, "1234567890", 5, S("12345"));
+    test(S(""), 0, "1234567890", 9, S("123456789"));
+    test(S(""), 0, "1234567890", 10, S("1234567890"));
+    test(S(""), 0, "12345678901234567890", 0, S(""));
+    test(S(""), 0, "12345678901234567890", 1, S("1"));
+    test(S(""), 0, "12345678901234567890", 10, S("1234567890"));
+    test(S(""), 0, "12345678901234567890", 19, S("1234567890123456789"));
+    test(S(""), 0, "12345678901234567890", 20, S("12345678901234567890"));
+    test(S(""), 1, "", 0, S("can't happen"));
+    test(S(""), 1, "12345", 0, S("can't happen"));
+    test(S(""), 1, "12345", 1, S("can't happen"));
+    test(S(""), 1, "12345", 2, S("can't happen"));
+    test(S(""), 1, "12345", 4, S("can't happen"));
+    test(S(""), 1, "12345", 5, S("can't happen"));
+    test(S(""), 1, "1234567890", 0, S("can't happen"));
+    test(S(""), 1, "1234567890", 1, S("can't happen"));
+    test(S(""), 1, "1234567890", 5, S("can't happen"));
+    test(S(""), 1, "1234567890", 9, S("can't happen"));
+    test(S(""), 1, "1234567890", 10, S("can't happen"));
+    test(S(""), 1, "12345678901234567890", 0, S("can't happen"));
+    test(S(""), 1, "12345678901234567890", 1, S("can't happen"));
+    test(S(""), 1, "12345678901234567890", 10, S("can't happen"));
+    test(S(""), 1, "12345678901234567890", 19, S("can't happen"));
+    test(S(""), 1, "12345678901234567890", 20, S("can't happen"));
+    test(S("abcde"), 0, "", 0, S("abcde"));
+    test(S("abcde"), 0, "12345", 0, S("abcde"));
+    test(S("abcde"), 0, "12345", 1, S("1abcde"));
+    test(S("abcde"), 0, "12345", 2, S("12abcde"));
+    test(S("abcde"), 0, "12345", 4, S("1234abcde"));
+    test(S("abcde"), 0, "12345", 5, S("12345abcde"));
+    test(S("abcde"), 0, "1234567890", 0, S("abcde"));
+    test(S("abcde"), 0, "1234567890", 1, S("1abcde"));
+    test(S("abcde"), 0, "1234567890", 5, S("12345abcde"));
+    test(S("abcde"), 0, "1234567890", 9, S("123456789abcde"));
+    test(S("abcde"), 0, "1234567890", 10, S("1234567890abcde"));
+    test(S("abcde"), 0, "12345678901234567890", 0, S("abcde"));
+    test(S("abcde"), 0, "12345678901234567890", 1, S("1abcde"));
+    test(S("abcde"), 0, "12345678901234567890", 10, S("1234567890abcde"));
+    test(S("abcde"), 0, "12345678901234567890", 19, S("1234567890123456789abcde"));
+    test(S("abcde"), 0, "12345678901234567890", 20, S("12345678901234567890abcde"));
+    test(S("abcde"), 1, "", 0, S("abcde"));
+    test(S("abcde"), 1, "12345", 0, S("abcde"));
+    test(S("abcde"), 1, "12345", 1, S("a1bcde"));
+    test(S("abcde"), 1, "12345", 2, S("a12bcde"));
+    test(S("abcde"), 1, "12345", 4, S("a1234bcde"));
+    test(S("abcde"), 1, "12345", 5, S("a12345bcde"));
+    test(S("abcde"), 1, "1234567890", 0, S("abcde"));
+    test(S("abcde"), 1, "1234567890", 1, S("a1bcde"));
+    test(S("abcde"), 1, "1234567890", 5, S("a12345bcde"));
+    test(S("abcde"), 1, "1234567890", 9, S("a123456789bcde"));
+    test(S("abcde"), 1, "1234567890", 10, S("a1234567890bcde"));
+    test(S("abcde"), 1, "12345678901234567890", 0, S("abcde"));
+    test(S("abcde"), 1, "12345678901234567890", 1, S("a1bcde"));
+    test(S("abcde"), 1, "12345678901234567890", 10, S("a1234567890bcde"));
+    test(S("abcde"), 1, "12345678901234567890", 19, S("a1234567890123456789bcde"));
+    test(S("abcde"), 1, "12345678901234567890", 20, S("a12345678901234567890bcde"));
+    test(S("abcde"), 2, "", 0, S("abcde"));
+    test(S("abcde"), 2, "12345", 0, S("abcde"));
+    test(S("abcde"), 2, "12345", 1, S("ab1cde"));
+    test(S("abcde"), 2, "12345", 2, S("ab12cde"));
+    test(S("abcde"), 2, "12345", 4, S("ab1234cde"));
+    test(S("abcde"), 2, "12345", 5, S("ab12345cde"));
+    test(S("abcde"), 2, "1234567890", 0, S("abcde"));
+    test(S("abcde"), 2, "1234567890", 1, S("ab1cde"));
+    test(S("abcde"), 2, "1234567890", 5, S("ab12345cde"));
+    test(S("abcde"), 2, "1234567890", 9, S("ab123456789cde"));
+    test(S("abcde"), 2, "1234567890", 10, S("ab1234567890cde"));
+    test(S("abcde"), 2, "12345678901234567890", 0, S("abcde"));
+    test(S("abcde"), 2, "12345678901234567890", 1, S("ab1cde"));
+    test(S("abcde"), 2, "12345678901234567890", 10, S("ab1234567890cde"));
+    test(S("abcde"), 2, "12345678901234567890", 19, S("ab1234567890123456789cde"));
+    test(S("abcde"), 2, "12345678901234567890", 20, S("ab12345678901234567890cde"));
+    test(S("abcde"), 4, "", 0, S("abcde"));
+    test(S("abcde"), 4, "12345", 0, S("abcde"));
+    test(S("abcde"), 4, "12345", 1, S("abcd1e"));
+    test(S("abcde"), 4, "12345", 2, S("abcd12e"));
+    test(S("abcde"), 4, "12345", 4, S("abcd1234e"));
+    test(S("abcde"), 4, "12345", 5, S("abcd12345e"));
+    test(S("abcde"), 4, "1234567890", 0, S("abcde"));
+    test(S("abcde"), 4, "1234567890", 1, S("abcd1e"));
+    test(S("abcde"), 4, "1234567890", 5, S("abcd12345e"));
+    test(S("abcde"), 4, "1234567890", 9, S("abcd123456789e"));
+    test(S("abcde"), 4, "1234567890", 10, S("abcd1234567890e"));
+    test(S("abcde"), 4, "12345678901234567890", 0, S("abcde"));
+    test(S("abcde"), 4, "12345678901234567890", 1, S("abcd1e"));
+    test(S("abcde"), 4, "12345678901234567890", 10, S("abcd1234567890e"));
+    test(S("abcde"), 4, "12345678901234567890", 19, S("abcd1234567890123456789e"));
+    test(S("abcde"), 4, "12345678901234567890", 20, S("abcd12345678901234567890e"));
+    test(S("abcde"), 5, "", 0, S("abcde"));
+    test(S("abcde"), 5, "12345", 0, S("abcde"));
+    test(S("abcde"), 5, "12345", 1, S("abcde1"));
+    test(S("abcde"), 5, "12345", 2, S("abcde12"));
+    test(S("abcde"), 5, "12345", 4, S("abcde1234"));
+    test(S("abcde"), 5, "12345", 5, S("abcde12345"));
+    test(S("abcde"), 5, "1234567890", 0, S("abcde"));
+    test(S("abcde"), 5, "1234567890", 1, S("abcde1"));
+    test(S("abcde"), 5, "1234567890", 5, S("abcde12345"));
+    test(S("abcde"), 5, "1234567890", 9, S("abcde123456789"));
+    test(S("abcde"), 5, "1234567890", 10, S("abcde1234567890"));
+    test(S("abcde"), 5, "12345678901234567890", 0, S("abcde"));
+    test(S("abcde"), 5, "12345678901234567890", 1, S("abcde1"));
+    test(S("abcde"), 5, "12345678901234567890", 10, S("abcde1234567890"));
+    test(S("abcde"), 5, "12345678901234567890", 19, S("abcde1234567890123456789"));
+    test(S("abcde"), 5, "12345678901234567890", 20, S("abcde12345678901234567890"));
+    test(S("abcde"), 6, "", 0, S("can't happen"));
+    test(S("abcde"), 6, "12345", 0, S("can't happen"));
+    test(S("abcde"), 6, "12345", 1, S("can't happen"));
+    test(S("abcde"), 6, "12345", 2, S("can't happen"));
+    test(S("abcde"), 6, "12345", 4, S("can't happen"));
+    test(S("abcde"), 6, "12345", 5, S("can't happen"));
+    test(S("abcde"), 6, "1234567890", 0, S("can't happen"));
+    test(S("abcde"), 6, "1234567890", 1, S("can't happen"));
+    test(S("abcde"), 6, "1234567890", 5, S("can't happen"));
+    test(S("abcde"), 6, "1234567890", 9, S("can't happen"));
+    test(S("abcde"), 6, "1234567890", 10, S("can't happen"));
+    test(S("abcde"), 6, "12345678901234567890", 0, S("can't happen"));
+    test(S("abcde"), 6, "12345678901234567890", 1, S("can't happen"));
+    test(S("abcde"), 6, "12345678901234567890", 10, S("can't happen"));
+    test(S("abcde"), 6, "12345678901234567890", 19, S("can't happen"));
+    test(S("abcde"), 6, "12345678901234567890", 20, S("can't happen"));
+    test(S("abcdefghij"), 0, "", 0, S("abcdefghij"));
+    test(S("abcdefghij"), 0, "12345", 0, S("abcdefghij"));
+    test(S("abcdefghij"), 0, "12345", 1, S("1abcdefghij"));
+    test(S("abcdefghij"), 0, "12345", 2, S("12abcdefghij"));
+    test(S("abcdefghij"), 0, "12345", 4, S("1234abcdefghij"));
+    test(S("abcdefghij"), 0, "12345", 5, S("12345abcdefghij"));
+    test(S("abcdefghij"), 0, "1234567890", 0, S("abcdefghij"));
+    test(S("abcdefghij"), 0, "1234567890", 1, S("1abcdefghij"));
+    test(S("abcdefghij"), 0, "1234567890", 5, S("12345abcdefghij"));
+    test(S("abcdefghij"), 0, "1234567890", 9, S("123456789abcdefghij"));
+    test(S("abcdefghij"), 0, "1234567890", 10, S("1234567890abcdefghij"));
+    test(S("abcdefghij"), 0, "12345678901234567890", 0, S("abcdefghij"));
+    test(S("abcdefghij"), 0, "12345678901234567890", 1, S("1abcdefghij"));
+    test(S("abcdefghij"), 0, "12345678901234567890", 10, S("1234567890abcdefghij"));
+    test(S("abcdefghij"), 0, "12345678901234567890", 19, S("1234567890123456789abcdefghij"));
+    test(S("abcdefghij"), 0, "12345678901234567890", 20, S("12345678901234567890abcdefghij"));
+    test(S("abcdefghij"), 1, "", 0, S("abcdefghij"));
+    test(S("abcdefghij"), 1, "12345", 0, S("abcdefghij"));
+    test(S("abcdefghij"), 1, "12345", 1, S("a1bcdefghij"));
+    test(S("abcdefghij"), 1, "12345", 2, S("a12bcdefghij"));
+    test(S("abcdefghij"), 1, "12345", 4, S("a1234bcdefghij"));
+    test(S("abcdefghij"), 1, "12345", 5, S("a12345bcdefghij"));
+    test(S("abcdefghij"), 1, "1234567890", 0, S("abcdefghij"));
+    test(S("abcdefghij"), 1, "1234567890", 1, S("a1bcdefghij"));
+    test(S("abcdefghij"), 1, "1234567890", 5, S("a12345bcdefghij"));
+    test(S("abcdefghij"), 1, "1234567890", 9, S("a123456789bcdefghij"));
+    test(S("abcdefghij"), 1, "1234567890", 10, S("a1234567890bcdefghij"));
+    test(S("abcdefghij"), 1, "12345678901234567890", 0, S("abcdefghij"));
+    test(S("abcdefghij"), 1, "12345678901234567890", 1, S("a1bcdefghij"));
+    test(S("abcdefghij"), 1, "12345678901234567890", 10, S("a1234567890bcdefghij"));
+    test(S("abcdefghij"), 1, "12345678901234567890", 19, S("a1234567890123456789bcdefghij"));
+    test(S("abcdefghij"), 1, "12345678901234567890", 20, S("a12345678901234567890bcdefghij"));
+    test(S("abcdefghij"), 5, "", 0, S("abcdefghij"));
+    test(S("abcdefghij"), 5, "12345", 0, S("abcdefghij"));
+    test(S("abcdefghij"), 5, "12345", 1, S("abcde1fghij"));
+    test(S("abcdefghij"), 5, "12345", 2, S("abcde12fghij"));
+    test(S("abcdefghij"), 5, "12345", 4, S("abcde1234fghij"));
+    test(S("abcdefghij"), 5, "12345", 5, S("abcde12345fghij"));
+    test(S("abcdefghij"), 5, "1234567890", 0, S("abcdefghij"));
+    test(S("abcdefghij"), 5, "1234567890", 1, S("abcde1fghij"));
+    test(S("abcdefghij"), 5, "1234567890", 5, S("abcde12345fghij"));
+    test(S("abcdefghij"), 5, "1234567890", 9, S("abcde123456789fghij"));
+    test(S("abcdefghij"), 5, "1234567890", 10, S("abcde1234567890fghij"));
+    test(S("abcdefghij"), 5, "12345678901234567890", 0, S("abcdefghij"));
+    test(S("abcdefghij"), 5, "12345678901234567890", 1, S("abcde1fghij"));
+    test(S("abcdefghij"), 5, "12345678901234567890", 10, S("abcde1234567890fghij"));
+    test(S("abcdefghij"), 5, "12345678901234567890", 19, S("abcde1234567890123456789fghij"));
+    test(S("abcdefghij"), 5, "12345678901234567890", 20, S("abcde12345678901234567890fghij"));
+    test(S("abcdefghij"), 9, "", 0, S("abcdefghij"));
+    test(S("abcdefghij"), 9, "12345", 0, S("abcdefghij"));
+    test(S("abcdefghij"), 9, "12345", 1, S("abcdefghi1j"));
+    test(S("abcdefghij"), 9, "12345", 2, S("abcdefghi12j"));
+    test(S("abcdefghij"), 9, "12345", 4, S("abcdefghi1234j"));
+    test(S("abcdefghij"), 9, "12345", 5, S("abcdefghi12345j"));
+    test(S("abcdefghij"), 9, "1234567890", 0, S("abcdefghij"));
+    test(S("abcdefghij"), 9, "1234567890", 1, S("abcdefghi1j"));
+    test(S("abcdefghij"), 9, "1234567890", 5, S("abcdefghi12345j"));
+    test(S("abcdefghij"), 9, "1234567890", 9, S("abcdefghi123456789j"));
+    test(S("abcdefghij"), 9, "1234567890", 10, S("abcdefghi1234567890j"));
+    test(S("abcdefghij"), 9, "12345678901234567890", 0, S("abcdefghij"));
+    test(S("abcdefghij"), 9, "12345678901234567890", 1, S("abcdefghi1j"));
+    test(S("abcdefghij"), 9, "12345678901234567890", 10, S("abcdefghi1234567890j"));
+    test(S("abcdefghij"), 9, "12345678901234567890", 19, S("abcdefghi1234567890123456789j"));
+    test(S("abcdefghij"), 9, "12345678901234567890", 20, S("abcdefghi12345678901234567890j"));
+    test(S("abcdefghij"), 10, "", 0, S("abcdefghij"));
+    test(S("abcdefghij"), 10, "12345", 0, S("abcdefghij"));
+    test(S("abcdefghij"), 10, "12345", 1, S("abcdefghij1"));
+    test(S("abcdefghij"), 10, "12345", 2, S("abcdefghij12"));
+    test(S("abcdefghij"), 10, "12345", 4, S("abcdefghij1234"));
+    test(S("abcdefghij"), 10, "12345", 5, S("abcdefghij12345"));
+    test(S("abcdefghij"), 10, "1234567890", 0, S("abcdefghij"));
+    test(S("abcdefghij"), 10, "1234567890", 1, S("abcdefghij1"));
+    test(S("abcdefghij"), 10, "1234567890", 5, S("abcdefghij12345"));
+    test(S("abcdefghij"), 10, "1234567890", 9, S("abcdefghij123456789"));
+    test(S("abcdefghij"), 10, "1234567890", 10, S("abcdefghij1234567890"));
+    test(S("abcdefghij"), 10, "12345678901234567890", 0, S("abcdefghij"));
+    test(S("abcdefghij"), 10, "12345678901234567890", 1, S("abcdefghij1"));
+    test(S("abcdefghij"), 10, "12345678901234567890", 10, S("abcdefghij1234567890"));
+    test(S("abcdefghij"), 10, "12345678901234567890", 19, S("abcdefghij1234567890123456789"));
+    test(S("abcdefghij"), 10, "12345678901234567890", 20, S("abcdefghij12345678901234567890"));
+    test(S("abcdefghij"), 11, "", 0, S("can't happen"));
+    test(S("abcdefghij"), 11, "12345", 0, S("can't happen"));
+    test(S("abcdefghij"), 11, "12345", 1, S("can't happen"));
+    test(S("abcdefghij"), 11, "12345", 2, S("can't happen"));
+    test(S("abcdefghij"), 11, "12345", 4, S("can't happen"));
+    test(S("abcdefghij"), 11, "12345", 5, S("can't happen"));
+    test(S("abcdefghij"), 11, "1234567890", 0, S("can't happen"));
+    test(S("abcdefghij"), 11, "1234567890", 1, S("can't happen"));
+    test(S("abcdefghij"), 11, "1234567890", 5, S("can't happen"));
+    test(S("abcdefghij"), 11, "1234567890", 9, S("can't happen"));
+    test(S("abcdefghij"), 11, "1234567890", 10, S("can't happen"));
+    test(S("abcdefghij"), 11, "12345678901234567890", 0, S("can't happen"));
+    test(S("abcdefghij"), 11, "12345678901234567890", 1, S("can't happen"));
+    test(S("abcdefghij"), 11, "12345678901234567890", 10, S("can't happen"));
+    test(S("abcdefghij"), 11, "12345678901234567890", 19, S("can't happen"));
+    test(S("abcdefghij"), 11, "12345678901234567890", 20, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 0, "", 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, "12345", 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, "12345", 1, S("1abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, "12345", 2, S("12abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, "12345", 4, S("1234abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, "12345", 5, S("12345abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, "1234567890", 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, "1234567890", 1, S("1abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, "1234567890", 5, S("12345abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, "1234567890", 9, S("123456789abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, "1234567890", 10, S("1234567890abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, "12345678901234567890", 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, "12345678901234567890", 1, S("1abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, "12345678901234567890", 10, S("1234567890abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, "12345678901234567890", 19, S("1234567890123456789abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, "12345678901234567890", 20, S("12345678901234567890abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, "", 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, "12345", 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, "12345", 1, S("a1bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, "12345", 2, S("a12bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, "12345", 4, S("a1234bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, "12345", 5, S("a12345bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, "1234567890", 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, "1234567890", 1, S("a1bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, "1234567890", 5, S("a12345bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, "1234567890", 9, S("a123456789bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, "1234567890", 10, S("a1234567890bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, "12345678901234567890", 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, "12345678901234567890", 1, S("a1bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, "12345678901234567890", 10, S("a1234567890bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, "12345678901234567890", 19, S("a1234567890123456789bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, "12345678901234567890", 20, S("a12345678901234567890bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, "", 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, "12345", 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, "12345", 1, S("abcdefghij1klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, "12345", 2, S("abcdefghij12klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, "12345", 4, S("abcdefghij1234klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, "12345", 5, S("abcdefghij12345klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, "1234567890", 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, "1234567890", 1, S("abcdefghij1klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, "1234567890", 5, S("abcdefghij12345klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, "1234567890", 9, S("abcdefghij123456789klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, "1234567890", 10, S("abcdefghij1234567890klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, "12345678901234567890", 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, "12345678901234567890", 1, S("abcdefghij1klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, "12345678901234567890", 10, S("abcdefghij1234567890klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, "12345678901234567890", 19, S("abcdefghij1234567890123456789klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, "12345678901234567890", 20, S("abcdefghij12345678901234567890klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 19, "", 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 19, "12345", 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 19, "12345", 1, S("abcdefghijklmnopqrs1t"));
+    test(S("abcdefghijklmnopqrst"), 19, "12345", 2, S("abcdefghijklmnopqrs12t"));
+    test(S("abcdefghijklmnopqrst"), 19, "12345", 4, S("abcdefghijklmnopqrs1234t"));
+    test(S("abcdefghijklmnopqrst"), 19, "12345", 5, S("abcdefghijklmnopqrs12345t"));
+    test(S("abcdefghijklmnopqrst"), 19, "1234567890", 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 19, "1234567890", 1, S("abcdefghijklmnopqrs1t"));
+    test(S("abcdefghijklmnopqrst"), 19, "1234567890", 5, S("abcdefghijklmnopqrs12345t"));
+    test(S("abcdefghijklmnopqrst"), 19, "1234567890", 9, S("abcdefghijklmnopqrs123456789t"));
+    test(S("abcdefghijklmnopqrst"), 19, "1234567890", 10, S("abcdefghijklmnopqrs1234567890t"));
+    test(S("abcdefghijklmnopqrst"), 19, "12345678901234567890", 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 19, "12345678901234567890", 1, S("abcdefghijklmnopqrs1t"));
+    test(S("abcdefghijklmnopqrst"), 19, "12345678901234567890", 10, S("abcdefghijklmnopqrs1234567890t"));
+    test(S("abcdefghijklmnopqrst"), 19, "12345678901234567890", 19, S("abcdefghijklmnopqrs1234567890123456789t"));
+    test(S("abcdefghijklmnopqrst"), 19, "12345678901234567890", 20, S("abcdefghijklmnopqrs12345678901234567890t"));
+    test(S("abcdefghijklmnopqrst"), 20, "", 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 20, "12345", 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 20, "12345", 1, S("abcdefghijklmnopqrst1"));
+    test(S("abcdefghijklmnopqrst"), 20, "12345", 2, S("abcdefghijklmnopqrst12"));
+    test(S("abcdefghijklmnopqrst"), 20, "12345", 4, S("abcdefghijklmnopqrst1234"));
+    test(S("abcdefghijklmnopqrst"), 20, "12345", 5, S("abcdefghijklmnopqrst12345"));
+    test(S("abcdefghijklmnopqrst"), 20, "1234567890", 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 20, "1234567890", 1, S("abcdefghijklmnopqrst1"));
+    test(S("abcdefghijklmnopqrst"), 20, "1234567890", 5, S("abcdefghijklmnopqrst12345"));
+    test(S("abcdefghijklmnopqrst"), 20, "1234567890", 9, S("abcdefghijklmnopqrst123456789"));
+    test(S("abcdefghijklmnopqrst"), 20, "1234567890", 10, S("abcdefghijklmnopqrst1234567890"));
+    test(S("abcdefghijklmnopqrst"), 20, "12345678901234567890", 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 20, "12345678901234567890", 1, S("abcdefghijklmnopqrst1"));
+    test(S("abcdefghijklmnopqrst"), 20, "12345678901234567890", 10, S("abcdefghijklmnopqrst1234567890"));
+    test(S("abcdefghijklmnopqrst"), 20, "12345678901234567890", 19, S("abcdefghijklmnopqrst1234567890123456789"));
+    test(S("abcdefghijklmnopqrst"), 20, "12345678901234567890", 20, S("abcdefghijklmnopqrst12345678901234567890"));
+    test(S("abcdefghijklmnopqrst"), 21, "", 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, "12345", 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, "12345", 1, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, "12345", 2, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, "12345", 4, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, "12345", 5, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, "1234567890", 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, "1234567890", 1, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, "1234567890", 5, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, "1234567890", 9, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, "1234567890", 10, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, "12345678901234567890", 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, "12345678901234567890", 1, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, "12345678901234567890", 10, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, "12345678901234567890", 19, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, "12345678901234567890", 20, S("can't happen"));
+}
diff --git a/libcxx/test/strings/basic.string/string.modifiers/string::insert/size_size_char.pass.cpp b/libcxx/test/strings/basic.string/string.modifiers/string::insert/size_size_char.pass.cpp
new file mode 100644
index 00000000000..280789a7446
--- /dev/null
+++ b/libcxx/test/strings/basic.string/string.modifiers/string::insert/size_size_char.pass.cpp
@@ -0,0 +1,123 @@
+//===----------------------------------------------------------------------===//
+//
+// ΚΚΚΚΚΚΚΚΚΚΚΚΚΚΚΚΚΚΚΚThe LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// <string>
+
+// basic_string<charT,traits,Allocator>& 
+//   insert(size_type pos, size_type n, charT c);
+
+#include <string>
+#include <stdexcept>
+#include <cassert>
+
+template <class S>
+void
+test(S s, typename S::size_type pos, typename S::size_type n,
+     typename S::value_type str, S expected)
+{
+    typename S::size_type old_size = s.size();
+    S s0 = s;
+    try
+    {
+        s.insert(pos, n, str);
+        assert(s.__invariants());
+        assert(pos <= old_size);
+        assert(s == expected);
+    }
+    catch (std::out_of_range&)
+    {
+        assert(pos > old_size);
+        assert(s == s0);
+    }
+}
+
+int main()
+{
+    typedef std::string S;
+    test(S(""), 0, 0, '1', S(""));
+    test(S(""), 0, 5, '1', S("11111"));
+    test(S(""), 0, 10, '1', S("1111111111"));
+    test(S(""), 0, 20, '1', S("11111111111111111111"));
+    test(S(""), 1, 0, '1', S("can't happen"));
+    test(S(""), 1, 5, '1', S("can't happen"));
+    test(S(""), 1, 10, '1', S("can't happen"));
+    test(S(""), 1, 20, '1', S("can't happen"));
+    test(S("abcde"), 0, 0, '1', S("abcde"));
+    test(S("abcde"), 0, 5, '1', S("11111abcde"));
+    test(S("abcde"), 0, 10, '1', S("1111111111abcde"));
+    test(S("abcde"), 0, 20, '1', S("11111111111111111111abcde"));
+    test(S("abcde"), 1, 0, '1', S("abcde"));
+    test(S("abcde"), 1, 5, '1', S("a11111bcde"));
+    test(S("abcde"), 1, 10, '1', S("a1111111111bcde"));
+    test(S("abcde"), 1, 20, '1', S("a11111111111111111111bcde"));
+    test(S("abcde"), 2, 0, '1', S("abcde"));
+    test(S("abcde"), 2, 5, '1', S("ab11111cde"));
+    test(S("abcde"), 2, 10, '1', S("ab1111111111cde"));
+    test(S("abcde"), 2, 20, '1', S("ab11111111111111111111cde"));
+    test(S("abcde"), 4, 0, '1', S("abcde"));
+    test(S("abcde"), 4, 5, '1', S("abcd11111e"));
+    test(S("abcde"), 4, 10, '1', S("abcd1111111111e"));
+    test(S("abcde"), 4, 20, '1', S("abcd11111111111111111111e"));
+    test(S("abcde"), 5, 0, '1', S("abcde"));
+    test(S("abcde"), 5, 5, '1', S("abcde11111"));
+    test(S("abcde"), 5, 10, '1', S("abcde1111111111"));
+    test(S("abcde"), 5, 20, '1', S("abcde11111111111111111111"));
+    test(S("abcde"), 6, 0, '1', S("can't happen"));
+    test(S("abcde"), 6, 5, '1', S("can't happen"));
+    test(S("abcde"), 6, 10, '1', S("can't happen"));
+    test(S("abcde"), 6, 20, '1', S("can't happen"));
+    test(S("abcdefghij"), 0, 0, '1', S("abcdefghij"));
+    test(S("abcdefghij"), 0, 5, '1', S("11111abcdefghij"));
+    test(S("abcdefghij"), 0, 10, '1', S("1111111111abcdefghij"));
+    test(S("abcdefghij"), 0, 20, '1', S("11111111111111111111abcdefghij"));
+    test(S("abcdefghij"), 1, 0, '1', S("abcdefghij"));
+    test(S("abcdefghij"), 1, 5, '1', S("a11111bcdefghij"));
+    test(S("abcdefghij"), 1, 10, '1', S("a1111111111bcdefghij"));
+    test(S("abcdefghij"), 1, 20, '1', S("a11111111111111111111bcdefghij"));
+    test(S("abcdefghij"), 5, 0, '1', S("abcdefghij"));
+    test(S("abcdefghij"), 5, 5, '1', S("abcde11111fghij"));
+    test(S("abcdefghij"), 5, 10, '1', S("abcde1111111111fghij"));
+    test(S("abcdefghij"), 5, 20, '1', S("abcde11111111111111111111fghij"));
+    test(S("abcdefghij"), 9, 0, '1', S("abcdefghij"));
+    test(S("abcdefghij"), 9, 5, '1', S("abcdefghi11111j"));
+    test(S("abcdefghij"), 9, 10, '1', S("abcdefghi1111111111j"));
+    test(S("abcdefghij"), 9, 20, '1', S("abcdefghi11111111111111111111j"));
+    test(S("abcdefghij"), 10, 0, '1', S("abcdefghij"));
+    test(S("abcdefghij"), 10, 5, '1', S("abcdefghij11111"));
+    test(S("abcdefghij"), 10, 10, '1', S("abcdefghij1111111111"));
+    test(S("abcdefghij"), 10, 20, '1', S("abcdefghij11111111111111111111"));
+    test(S("abcdefghij"), 11, 0, '1', S("can't happen"));
+    test(S("abcdefghij"), 11, 5, '1', S("can't happen"));
+    test(S("abcdefghij"), 11, 10, '1', S("can't happen"));
+    test(S("abcdefghij"), 11, 20, '1', S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 0, 0, '1', S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 5, '1', S("11111abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 10, '1', S("1111111111abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, 20, '1', S("11111111111111111111abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 0, '1', S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 5, '1', S("a11111bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 10, '1', S("a1111111111bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, 20, '1', S("a11111111111111111111bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 0, '1', S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 5, '1', S("abcdefghij11111klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 10, '1', S("abcdefghij1111111111klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, 20, '1', S("abcdefghij11111111111111111111klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 19, 0, '1', S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 19, 5, '1', S("abcdefghijklmnopqrs11111t"));
+    test(S("abcdefghijklmnopqrst"), 19, 10, '1', S("abcdefghijklmnopqrs1111111111t"));
+    test(S("abcdefghijklmnopqrst"), 19, 20, '1', S("abcdefghijklmnopqrs11111111111111111111t"));
+    test(S("abcdefghijklmnopqrst"), 20, 0, '1', S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 20, 5, '1', S("abcdefghijklmnopqrst11111"));
+    test(S("abcdefghijklmnopqrst"), 20, 10, '1', S("abcdefghijklmnopqrst1111111111"));
+    test(S("abcdefghijklmnopqrst"), 20, 20, '1', S("abcdefghijklmnopqrst11111111111111111111"));
+    test(S("abcdefghijklmnopqrst"), 21, 0, '1', S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, 5, '1', S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, 10, '1', S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, 20, '1', S("can't happen"));
+}
diff --git a/libcxx/test/strings/basic.string/string.modifiers/string::insert/size_string.pass.cpp b/libcxx/test/strings/basic.string/string.modifiers/string::insert/size_string.pass.cpp
new file mode 100644
index 00000000000..7b2bd84234e
--- /dev/null
+++ b/libcxx/test/strings/basic.string/string.modifiers/string::insert/size_string.pass.cpp
@@ -0,0 +1,122 @@
+//===----------------------------------------------------------------------===//
+//
+// ΚΚΚΚΚΚΚΚΚΚΚΚΚΚΚΚΚΚΚΚThe LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// <string>
+
+// basic_string<charT,traits,Allocator>& 
+//   insert(size_type pos1, const basic_string& str);
+
+#include <string>
+#include <stdexcept>
+#include <cassert>
+
+template <class S>
+void
+test(S s, typename S::size_type pos, S str, S expected)
+{
+    typename S::size_type old_size = s.size();
+    S s0 = s;
+    try
+    {
+        s.insert(pos, str);
+        assert(s.__invariants());
+        assert(pos <= old_size);
+        assert(s == expected);
+    }
+    catch (std::out_of_range&)
+    {
+        assert(pos > old_size);
+        assert(s == s0);
+    }
+}
+
+int main()
+{
+    typedef std::string S;
+    test(S(""), 0, S(""), S(""));
+    test(S(""), 0, S("12345"), S("12345"));
+    test(S(""), 0, S("1234567890"), S("1234567890"));
+    test(S(""), 0, S("12345678901234567890"), S("12345678901234567890"));
+    test(S(""), 1, S(""), S("can't happen"));
+    test(S(""), 1, S("12345"), S("can't happen"));
+    test(S(""), 1, S("1234567890"), S("can't happen"));
+    test(S(""), 1, S("12345678901234567890"), S("can't happen"));
+    test(S("abcde"), 0, S(""), S("abcde"));
+    test(S("abcde"), 0, S("12345"), S("12345abcde"));
+    test(S("abcde"), 0, S("1234567890"), S("1234567890abcde"));
+    test(S("abcde"), 0, S("12345678901234567890"), S("12345678901234567890abcde"));
+    test(S("abcde"), 1, S(""), S("abcde"));
+    test(S("abcde"), 1, S("12345"), S("a12345bcde"));
+    test(S("abcde"), 1, S("1234567890"), S("a1234567890bcde"));
+    test(S("abcde"), 1, S("12345678901234567890"), S("a12345678901234567890bcde"));
+    test(S("abcde"), 2, S(""), S("abcde"));
+    test(S("abcde"), 2, S("12345"), S("ab12345cde"));
+    test(S("abcde"), 2, S("1234567890"), S("ab1234567890cde"));
+    test(S("abcde"), 2, S("12345678901234567890"), S("ab12345678901234567890cde"));
+    test(S("abcde"), 4, S(""), S("abcde"));
+    test(S("abcde"), 4, S("12345"), S("abcd12345e"));
+    test(S("abcde"), 4, S("1234567890"), S("abcd1234567890e"));
+    test(S("abcde"), 4, S("12345678901234567890"), S("abcd12345678901234567890e"));
+    test(S("abcde"), 5, S(""), S("abcde"));
+    test(S("abcde"), 5, S("12345"), S("abcde12345"));
+    test(S("abcde"), 5, S("1234567890"), S("abcde1234567890"));
+    test(S("abcde"), 5, S("12345678901234567890"), S("abcde12345678901234567890"));
+    test(S("abcde"), 6, S(""), S("can't happen"));
+    test(S("abcde"), 6, S("12345"), S("can't happen"));
+    test(S("abcde"), 6, S("1234567890"), S("can't happen"));
+    test(S("abcde"), 6, S("12345678901234567890"), S("can't happen"));
+    test(S("abcdefghij"), 0, S(""), S("abcdefghij"));
+    test(S("abcdefghij"), 0, S("12345"), S("12345abcdefghij"));
+    test(S("abcdefghij"), 0, S("1234567890"), S("1234567890abcdefghij"));
+    test(S("abcdefghij"), 0, S("12345678901234567890"), S("12345678901234567890abcdefghij"));
+    test(S("abcdefghij"), 1, S(""), S("abcdefghij"));
+    test(S("abcdefghij"), 1, S("12345"), S("a12345bcdefghij"));
+    test(S("abcdefghij"), 1, S("1234567890"), S("a1234567890bcdefghij"));
+    test(S("abcdefghij"), 1, S("12345678901234567890"), S("a12345678901234567890bcdefghij"));
+    test(S("abcdefghij"), 5, S(""), S("abcdefghij"));
+    test(S("abcdefghij"), 5, S("12345"), S("abcde12345fghij"));
+    test(S("abcdefghij"), 5, S("1234567890"), S("abcde1234567890fghij"));
+    test(S("abcdefghij"), 5, S("12345678901234567890"), S("abcde12345678901234567890fghij"));
+    test(S("abcdefghij"), 9, S(""), S("abcdefghij"));
+    test(S("abcdefghij"), 9, S("12345"), S("abcdefghi12345j"));
+    test(S("abcdefghij"), 9, S("1234567890"), S("abcdefghi1234567890j"));
+    test(S("abcdefghij"), 9, S("12345678901234567890"), S("abcdefghi12345678901234567890j"));
+    test(S("abcdefghij"), 10, S(""), S("abcdefghij"));
+    test(S("abcdefghij"), 10, S("12345"), S("abcdefghij12345"));
+    test(S("abcdefghij"), 10, S("1234567890"), S("abcdefghij1234567890"));
+    test(S("abcdefghij"), 10, S("12345678901234567890"), S("abcdefghij12345678901234567890"));
+    test(S("abcdefghij"), 11, S(""), S("can't happen"));
+    test(S("abcdefghij"), 11, S("12345"), S("can't happen"));
+    test(S("abcdefghij"), 11, S("1234567890"), S("can't happen"));
+    test(S("abcdefghij"), 11, S("12345678901234567890"), S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 0, S(""), S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, S("12345"), S("12345abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, S("1234567890"), S("1234567890abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, S("12345678901234567890"), S("12345678901234567890abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, S(""), S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, S("12345"), S("a12345bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, S("1234567890"), S("a1234567890bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, S("12345678901234567890"), S("a12345678901234567890bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, S(""), S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, S("12345"), S("abcdefghij12345klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, S("1234567890"), S("abcdefghij1234567890klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, S("12345678901234567890"), S("abcdefghij12345678901234567890klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 19, S(""), S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 19, S("12345"), S("abcdefghijklmnopqrs12345t"));
+    test(S("abcdefghijklmnopqrst"), 19, S("1234567890"), S("abcdefghijklmnopqrs1234567890t"));
+    test(S("abcdefghijklmnopqrst"), 19, S("12345678901234567890"), S("abcdefghijklmnopqrs12345678901234567890t"));
+    test(S("abcdefghijklmnopqrst"), 20, S(""), S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 20, S("12345"), S("abcdefghijklmnopqrst12345"));
+    test(S("abcdefghijklmnopqrst"), 20, S("1234567890"), S("abcdefghijklmnopqrst1234567890"));
+    test(S("abcdefghijklmnopqrst"), 20, S("12345678901234567890"), S("abcdefghijklmnopqrst12345678901234567890"));
+    test(S("abcdefghijklmnopqrst"), 21, S(""), S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, S("12345"), S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, S("1234567890"), S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, S("12345678901234567890"), S("can't happen"));
+}
diff --git a/libcxx/test/strings/basic.string/string.modifiers/string::insert/size_string_size_size.pass.cpp b/libcxx/test/strings/basic.string/string.modifiers/string::insert/size_string_size_size.pass.cpp
new file mode 100644
index 00000000000..aa076a51132
--- /dev/null
+++ b/libcxx/test/strings/basic.string/string.modifiers/string::insert/size_string_size_size.pass.cpp
@@ -0,0 +1,1674 @@
+//===----------------------------------------------------------------------===//
+//
+// ΚΚΚΚΚΚΚΚΚΚΚΚΚΚΚΚΚΚΚΚThe LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// <string>
+
+// basic_string<charT,traits,Allocator>& 
+//   insert(size_type pos1, const basic_string<charT,traits,Allocator>& str, 
+//          size_type pos2, size_type n);
+
+#include <string>
+#include <stdexcept>
+#include <cassert>
+
+typedef std::string S;
+
+void
+test(S s, S::size_type pos1, S str, S::size_type pos2,
+     S::size_type n, S expected)
+{
+    S::size_type old_size = s.size();
+    S s0 = s;
+    try
+    {
+        s.insert(pos1, str, pos2, n);
+        assert(s.__invariants());
+        assert(pos1 <= old_size && pos2 <= str.size());
+        assert(s == expected);
+    }
+    catch (std::out_of_range&)
+    {
+        assert(pos1 > old_size || pos2 > str.size());
+        assert(s == s0);
+    }
+}
+
+void test0()
+{
+    test(S(""), 0, S(""), 0, 0, S(""));
+    test(S(""), 0, S(""), 0, 1, S(""));
+    test(S(""), 0, S(""), 1, 0, S("can't happen"));
+    test(S(""), 0, S("12345"), 0, 0, S(""));
+    test(S(""), 0, S("12345"), 0, 1, S("1"));
+    test(S(""), 0, S("12345"), 0, 2, S("12"));
+    test(S(""), 0, S("12345"), 0, 4, S("1234"));
+    test(S(""), 0, S("12345"), 0, 5, S("12345"));
+    test(S(""), 0, S("12345"), 0, 6, S("12345"));
+    test(S(""), 0, S("12345"), 1, 0, S(""));
+    test(S(""), 0, S("12345"), 1, 1, S("2"));
+    test(S(""), 0, S("12345"), 1, 2, S("23"));
+    test(S(""), 0, S("12345"), 1, 3, S("234"));
+    test(S(""), 0, S("12345"), 1, 4, S("2345"));
+    test(S(""), 0, S("12345"), 1, 5, S("2345"));
+    test(S(""), 0, S("12345"), 2, 0, S(""));
+    test(S(""), 0, S("12345"), 2, 1, S("3"));
+    test(S(""), 0, S("12345"), 2, 2, S("34"));
+    test(S(""), 0, S("12345"), 2, 3, S("345"));
+    test(S(""), 0, S("12345"), 2, 4, S("345"));
+    test(S(""), 0, S("12345"), 4, 0, S(""));
+    test(S(""), 0, S("12345"), 4, 1, S("5"));
+    test(S(""), 0, S("12345"), 4, 2, S("5"));
+    test(S(""), 0, S("12345"), 5, 0, S(""));
+    test(S(""), 0, S("12345"), 5, 1, S(""));
+    test(S(""), 0, S("12345"), 6, 0, S("can't happen"));
+    test(S(""), 0, S("1234567890"), 0, 0, S(""));
+    test(S(""), 0, S("1234567890"), 0, 1, S("1"));
+    test(S(""), 0, S("1234567890"), 0, 5, S("12345"));
+    test(S(""), 0, S("1234567890"), 0, 9, S("123456789"));
+    test(S(""), 0, S("1234567890"), 0, 10, S("1234567890"));
+    test(S(""), 0, S("1234567890"), 0, 11, S("1234567890"));
+    test(S(""), 0, S("1234567890"), 1, 0, S(""));
+    test(S(""), 0, S("1234567890"), 1, 1, S("2"));
+    test(S(""), 0, S("1234567890"), 1, 4, S("2345"));
+    test(S(""), 0, S("1234567890"), 1, 8, S("23456789"));
+    test(S(""), 0, S("1234567890"), 1, 9, S("234567890"));
+    test(S(""), 0, S("1234567890"), 1, 10, S("234567890"));
+    test(S(""), 0, S("1234567890"), 5, 0, S(""));
+    test(S(""), 0, S("1234567890"), 5, 1, S("6"));
+    test(S(""), 0, S("1234567890"), 5, 2, S("67"));
+    test(S(""), 0, S("1234567890"), 5, 4, S("6789"));
+    test(S(""), 0, S("1234567890"), 5, 5, S("67890"));
+    test(S(""), 0, S("1234567890"), 5, 6, S("67890"));
+    test(S(""), 0, S("1234567890"), 9, 0, S(""));
+    test(S(""), 0, S("1234567890"), 9, 1, S("0"));
+    test(S(""), 0, S("1234567890"), 9, 2, S("0"));
+    test(S(""), 0, S("1234567890"), 10, 0, S(""));
+    test(S(""), 0, S("1234567890"), 10, 1, S(""));
+    test(S(""), 0, S("1234567890"), 11, 0, S("can't happen"));
+}
+
+void test1()
+{
+    test(S(""), 0, S("12345678901234567890"), 0, 0, S(""));
+    test(S(""), 0, S("12345678901234567890"), 0, 1, S("1"));
+    test(S(""), 0, S("12345678901234567890"), 0, 10, S("1234567890"));
+    test(S(""), 0, S("12345678901234567890"), 0, 19, S("1234567890123456789"));
+    test(S(""), 0, S("12345678901234567890"), 0, 20, S("12345678901234567890"));
+    test(S(""), 0, S("12345678901234567890"), 0, 21, S("12345678901234567890"));
+    test(S(""), 0, S("12345678901234567890"), 1, 0, S(""));
+    test(S(""), 0, S("12345678901234567890"), 1, 1, S("2"));
+    test(S(""), 0, S("12345678901234567890"), 1, 9, S("234567890"));
+    test(S(""), 0, S("12345678901234567890"), 1, 18, S("234567890123456789"));
+    test(S(""), 0, S("12345678901234567890"), 1, 19, S("2345678901234567890"));
+    test(S(""), 0, S("12345678901234567890"), 1, 20, S("2345678901234567890"));
+    test(S(""), 0, S("12345678901234567890"), 10, 0, S(""));
+    test(S(""), 0, S("12345678901234567890"), 10, 1, S("1"));
+    test(S(""), 0, S("12345678901234567890"), 10, 5, S("12345"));
+    test(S(""), 0, S("12345678901234567890"), 10, 9, S("123456789"));
+    test(S(""), 0, S("12345678901234567890"), 10, 10, S("1234567890"));
+    test(S(""), 0, S("12345678901234567890"), 10, 11, S("1234567890"));
+    test(S(""), 0, S("12345678901234567890"), 19, 0, S(""));
+    test(S(""), 0, S("12345678901234567890"), 19, 1, S("0"));
+    test(S(""), 0, S("12345678901234567890"), 19, 2, S("0"));
+    test(S(""), 0, S("12345678901234567890"), 20, 0, S(""));
+    test(S(""), 0, S("12345678901234567890"), 20, 1, S(""));
+    test(S(""), 0, S("12345678901234567890"), 21, 0, S("can't happen"));
+    test(S(""), 1, S(""), 0, 0, S("can't happen"));
+    test(S(""), 1, S(""), 0, 1, S("can't happen"));
+    test(S(""), 1, S(""), 1, 0, S("can't happen"));
+    test(S(""), 1, S("12345"), 0, 0, S("can't happen"));
+    test(S(""), 1, S("12345"), 0, 1, S("can't happen"));
+    test(S(""), 1, S("12345"), 0, 2, S("can't happen"));
+    test(S(""), 1, S("12345"), 0, 4, S("can't happen"));
+    test(S(""), 1, S("12345"), 0, 5, S("can't happen"));
+    test(S(""), 1, S("12345"), 0, 6, S("can't happen"));
+    test(S(""), 1, S("12345"), 1, 0, S("can't happen"));
+    test(S(""), 1, S("12345"), 1, 1, S("can't happen"));
+    test(S(""), 1, S("12345"), 1, 2, S("can't happen"));
+    test(S(""), 1, S("12345"), 1, 3, S("can't happen"));
+    test(S(""), 1, S("12345"), 1, 4, S("can't happen"));
+    test(S(""), 1, S("12345"), 1, 5, S("can't happen"));
+    test(S(""), 1, S("12345"), 2, 0, S("can't happen"));
+    test(S(""), 1, S("12345"), 2, 1, S("can't happen"));
+    test(S(""), 1, S("12345"), 2, 2, S("can't happen"));
+    test(S(""), 1, S("12345"), 2, 3, S("can't happen"));
+    test(S(""), 1, S("12345"), 2, 4, S("can't happen"));
+    test(S(""), 1, S("12345"), 4, 0, S("can't happen"));
+    test(S(""), 1, S("12345"), 4, 1, S("can't happen"));
+    test(S(""), 1, S("12345"), 4, 2, S("can't happen"));
+    test(S(""), 1, S("12345"), 5, 0, S("can't happen"));
+    test(S(""), 1, S("12345"), 5, 1, S("can't happen"));
+    test(S(""), 1, S("12345"), 6, 0, S("can't happen"));
+}
+
+void test2()
+{
+    test(S(""), 1, S("1234567890"), 0, 0, S("can't happen"));
+    test(S(""), 1, S("1234567890"), 0, 1, S("can't happen"));
+    test(S(""), 1, S("1234567890"), 0, 5, S("can't happen"));
+    test(S(""), 1, S("1234567890"), 0, 9, S("can't happen"));
+    test(S(""), 1, S("1234567890"), 0, 10, S("can't happen"));
+    test(S(""), 1, S("1234567890"), 0, 11, S("can't happen"));
+    test(S(""), 1, S("1234567890"), 1, 0, S("can't happen"));
+    test(S(""), 1, S("1234567890"), 1, 1, S("can't happen"));
+    test(S(""), 1, S("1234567890"), 1, 4, S("can't happen"));
+    test(S(""), 1, S("1234567890"), 1, 8, S("can't happen"));
+    test(S(""), 1, S("1234567890"), 1, 9, S("can't happen"));
+    test(S(""), 1, S("1234567890"), 1, 10, S("can't happen"));
+    test(S(""), 1, S("1234567890"), 5, 0, S("can't happen"));
+    test(S(""), 1, S("1234567890"), 5, 1, S("can't happen"));
+    test(S(""), 1, S("1234567890"), 5, 2, S("can't happen"));
+    test(S(""), 1, S("1234567890"), 5, 4, S("can't happen"));
+    test(S(""), 1, S("1234567890"), 5, 5, S("can't happen"));
+    test(S(""), 1, S("1234567890"), 5, 6, S("can't happen"));
+    test(S(""), 1, S("1234567890"), 9, 0, S("can't happen"));
+    test(S(""), 1, S("1234567890"), 9, 1, S("can't happen"));
+    test(S(""), 1, S("1234567890"), 9, 2, S("can't happen"));
+    test(S(""), 1, S("1234567890"), 10, 0, S("can't happen"));
+    test(S(""), 1, S("1234567890"), 10, 1, S("can't happen"));
+    test(S(""), 1, S("1234567890"), 11, 0, S("can't happen"));
+    test(S(""), 1, S("12345678901234567890"), 0, 0, S("can't happen"));
+    test(S(""), 1, S("12345678901234567890"), 0, 1, S("can't happen"));
+    test(S(""), 1, S("12345678901234567890"), 0, 10, S("can't happen"));
+    test(S(""), 1, S("12345678901234567890"), 0, 19, S("can't happen"));
+    test(S(""), 1, S("12345678901234567890"), 0, 20, S("can't happen"));
+    test(S(""), 1, S("12345678901234567890"), 0, 21, S("can't happen"));
+    test(S(""), 1, S("12345678901234567890"), 1, 0, S("can't happen"));
+    test(S(""), 1, S("12345678901234567890"), 1, 1, S("can't happen"));
+    test(S(""), 1, S("12345678901234567890"), 1, 9, S("can't happen"));
+    test(S(""), 1, S("12345678901234567890"), 1, 18, S("can't happen"));
+    test(S(""), 1, S("12345678901234567890"), 1, 19, S("can't happen"));
+    test(S(""), 1, S("12345678901234567890"), 1, 20, S("can't happen"));
+    test(S(""), 1, S("12345678901234567890"), 10, 0, S("can't happen"));
+    test(S(""), 1, S("12345678901234567890"), 10, 1, S("can't happen"));
+    test(S(""), 1, S("12345678901234567890"), 10, 5, S("can't happen"));
+    test(S(""), 1, S("12345678901234567890"), 10, 9, S("can't happen"));
+    test(S(""), 1, S("12345678901234567890"), 10, 10, S("can't happen"));
+    test(S(""), 1, S("12345678901234567890"), 10, 11, S("can't happen"));
+    test(S(""), 1, S("12345678901234567890"), 19, 0, S("can't happen"));
+    test(S(""), 1, S("12345678901234567890"), 19, 1, S("can't happen"));
+    test(S(""), 1, S("12345678901234567890"), 19, 2, S("can't happen"));
+    test(S(""), 1, S("12345678901234567890"), 20, 0, S("can't happen"));
+    test(S(""), 1, S("12345678901234567890"), 20, 1, S("can't happen"));
+    test(S(""), 1, S("12345678901234567890"), 21, 0, S("can't happen"));
+    test(S("abcde"), 0, S(""), 0, 0, S("abcde"));
+    test(S("abcde"), 0, S(""), 0, 1, S("abcde"));
+}
+
+void test3()
+{
+    test(S("abcde"), 0, S(""), 1, 0, S("can't happen"));
+    test(S("abcde"), 0, S("12345"), 0, 0, S("abcde"));
+    test(S("abcde"), 0, S("12345"), 0, 1, S("1abcde"));
+    test(S("abcde"), 0, S("12345"), 0, 2, S("12abcde"));
+    test(S("abcde"), 0, S("12345"), 0, 4, S("1234abcde"));
+    test(S("abcde"), 0, S("12345"), 0, 5, S("12345abcde"));
+    test(S("abcde"), 0, S("12345"), 0, 6, S("12345abcde"));
+    test(S("abcde"), 0, S("12345"), 1, 0, S("abcde"));
+    test(S("abcde"), 0, S("12345"), 1, 1, S("2abcde"));
+    test(S("abcde"), 0, S("12345"), 1, 2, S("23abcde"));
+    test(S("abcde"), 0, S("12345"), 1, 3, S("234abcde"));
+    test(S("abcde"), 0, S("12345"), 1, 4, S("2345abcde"));
+    test(S("abcde"), 0, S("12345"), 1, 5, S("2345abcde"));
+    test(S("abcde"), 0, S("12345"), 2, 0, S("abcde"));
+    test(S("abcde"), 0, S("12345"), 2, 1, S("3abcde"));
+    test(S("abcde"), 0, S("12345"), 2, 2, S("34abcde"));
+    test(S("abcde"), 0, S("12345"), 2, 3, S("345abcde"));
+    test(S("abcde"), 0, S("12345"), 2, 4, S("345abcde"));
+    test(S("abcde"), 0, S("12345"), 4, 0, S("abcde"));
+    test(S("abcde"), 0, S("12345"), 4, 1, S("5abcde"));
+    test(S("abcde"), 0, S("12345"), 4, 2, S("5abcde"));
+    test(S("abcde"), 0, S("12345"), 5, 0, S("abcde"));
+    test(S("abcde"), 0, S("12345"), 5, 1, S("abcde"));
+    test(S("abcde"), 0, S("12345"), 6, 0, S("can't happen"));
+    test(S("abcde"), 0, S("1234567890"), 0, 0, S("abcde"));
+    test(S("abcde"), 0, S("1234567890"), 0, 1, S("1abcde"));
+    test(S("abcde"), 0, S("1234567890"), 0, 5, S("12345abcde"));
+    test(S("abcde"), 0, S("1234567890"), 0, 9, S("123456789abcde"));
+    test(S("abcde"), 0, S("1234567890"), 0, 10, S("1234567890abcde"));
+    test(S("abcde"), 0, S("1234567890"), 0, 11, S("1234567890abcde"));
+    test(S("abcde"), 0, S("1234567890"), 1, 0, S("abcde"));
+    test(S("abcde"), 0, S("1234567890"), 1, 1, S("2abcde"));
+    test(S("abcde"), 0, S("1234567890"), 1, 4, S("2345abcde"));
+    test(S("abcde"), 0, S("1234567890"), 1, 8, S("23456789abcde"));
+    test(S("abcde"), 0, S("1234567890"), 1, 9, S("234567890abcde"));
+    test(S("abcde"), 0, S("1234567890"), 1, 10, S("234567890abcde"));
+    test(S("abcde"), 0, S("1234567890"), 5, 0, S("abcde"));
+    test(S("abcde"), 0, S("1234567890"), 5, 1, S("6abcde"));
+    test(S("abcde"), 0, S("1234567890"), 5, 2, S("67abcde"));
+    test(S("abcde"), 0, S("1234567890"), 5, 4, S("6789abcde"));
+    test(S("abcde"), 0, S("1234567890"), 5, 5, S("67890abcde"));
+    test(S("abcde"), 0, S("1234567890"), 5, 6, S("67890abcde"));
+    test(S("abcde"), 0, S("1234567890"), 9, 0, S("abcde"));
+    test(S("abcde"), 0, S("1234567890"), 9, 1, S("0abcde"));
+    test(S("abcde"), 0, S("1234567890"), 9, 2, S("0abcde"));
+    test(S("abcde"), 0, S("1234567890"), 10, 0, S("abcde"));
+    test(S("abcde"), 0, S("1234567890"), 10, 1, S("abcde"));
+    test(S("abcde"), 0, S("1234567890"), 11, 0, S("can't happen"));
+    test(S("abcde"), 0, S("12345678901234567890"), 0, 0, S("abcde"));
+    test(S("abcde"), 0, S("12345678901234567890"), 0, 1, S("1abcde"));
+}
+
+void test4()
+{
+    test(S("abcde"), 0, S("12345678901234567890"), 0, 10, S("1234567890abcde"));
+    test(S("abcde"), 0, S("12345678901234567890"), 0, 19, S("1234567890123456789abcde"));
+    test(S("abcde"), 0, S("12345678901234567890"), 0, 20, S("12345678901234567890abcde"));
+    test(S("abcde"), 0, S("12345678901234567890"), 0, 21, S("12345678901234567890abcde"));
+    test(S("abcde"), 0, S("12345678901234567890"), 1, 0, S("abcde"));
+    test(S("abcde"), 0, S("12345678901234567890"), 1, 1, S("2abcde"));
+    test(S("abcde"), 0, S("12345678901234567890"), 1, 9, S("234567890abcde"));
+    test(S("abcde"), 0, S("12345678901234567890"), 1, 18, S("234567890123456789abcde"));
+    test(S("abcde"), 0, S("12345678901234567890"), 1, 19, S("2345678901234567890abcde"));
+    test(S("abcde"), 0, S("12345678901234567890"), 1, 20, S("2345678901234567890abcde"));
+    test(S("abcde"), 0, S("12345678901234567890"), 10, 0, S("abcde"));
+    test(S("abcde"), 0, S("12345678901234567890"), 10, 1, S("1abcde"));
+    test(S("abcde"), 0, S("12345678901234567890"), 10, 5, S("12345abcde"));
+    test(S("abcde"), 0, S("12345678901234567890"), 10, 9, S("123456789abcde"));
+    test(S("abcde"), 0, S("12345678901234567890"), 10, 10, S("1234567890abcde"));
+    test(S("abcde"), 0, S("12345678901234567890"), 10, 11, S("1234567890abcde"));
+    test(S("abcde"), 0, S("12345678901234567890"), 19, 0, S("abcde"));
+    test(S("abcde"), 0, S("12345678901234567890"), 19, 1, S("0abcde"));
+    test(S("abcde"), 0, S("12345678901234567890"), 19, 2, S("0abcde"));
+    test(S("abcde"), 0, S("12345678901234567890"), 20, 0, S("abcde"));
+    test(S("abcde"), 0, S("12345678901234567890"), 20, 1, S("abcde"));
+    test(S("abcde"), 0, S("12345678901234567890"), 21, 0, S("can't happen"));
+    test(S("abcde"), 1, S(""), 0, 0, S("abcde"));
+    test(S("abcde"), 1, S(""), 0, 1, S("abcde"));
+    test(S("abcde"), 1, S(""), 1, 0, S("can't happen"));
+    test(S("abcde"), 1, S("12345"), 0, 0, S("abcde"));
+    test(S("abcde"), 1, S("12345"), 0, 1, S("a1bcde"));
+    test(S("abcde"), 1, S("12345"), 0, 2, S("a12bcde"));
+    test(S("abcde"), 1, S("12345"), 0, 4, S("a1234bcde"));
+    test(S("abcde"), 1, S("12345"), 0, 5, S("a12345bcde"));
+    test(S("abcde"), 1, S("12345"), 0, 6, S("a12345bcde"));
+    test(S("abcde"), 1, S("12345"), 1, 0, S("abcde"));
+    test(S("abcde"), 1, S("12345"), 1, 1, S("a2bcde"));
+    test(S("abcde"), 1, S("12345"), 1, 2, S("a23bcde"));
+    test(S("abcde"), 1, S("12345"), 1, 3, S("a234bcde"));
+    test(S("abcde"), 1, S("12345"), 1, 4, S("a2345bcde"));
+    test(S("abcde"), 1, S("12345"), 1, 5, S("a2345bcde"));
+    test(S("abcde"), 1, S("12345"), 2, 0, S("abcde"));
+    test(S("abcde"), 1, S("12345"), 2, 1, S("a3bcde"));
+    test(S("abcde"), 1, S("12345"), 2, 2, S("a34bcde"));
+    test(S("abcde"), 1, S("12345"), 2, 3, S("a345bcde"));
+    test(S("abcde"), 1, S("12345"), 2, 4, S("a345bcde"));
+    test(S("abcde"), 1, S("12345"), 4, 0, S("abcde"));
+    test(S("abcde"), 1, S("12345"), 4, 1, S("a5bcde"));
+    test(S("abcde"), 1, S("12345"), 4, 2, S("a5bcde"));
+    test(S("abcde"), 1, S("12345"), 5, 0, S("abcde"));
+    test(S("abcde"), 1, S("12345"), 5, 1, S("abcde"));
+    test(S("abcde"), 1, S("12345"), 6, 0, S("can't happen"));
+    test(S("abcde"), 1, S("1234567890"), 0, 0, S("abcde"));
+    test(S("abcde"), 1, S("1234567890"), 0, 1, S("a1bcde"));
+}
+
+void test5()
+{
+    test(S("abcde"), 1, S("1234567890"), 0, 5, S("a12345bcde"));
+    test(S("abcde"), 1, S("1234567890"), 0, 9, S("a123456789bcde"));
+    test(S("abcde"), 1, S("1234567890"), 0, 10, S("a1234567890bcde"));
+    test(S("abcde"), 1, S("1234567890"), 0, 11, S("a1234567890bcde"));
+    test(S("abcde"), 1, S("1234567890"), 1, 0, S("abcde"));
+    test(S("abcde"), 1, S("1234567890"), 1, 1, S("a2bcde"));
+    test(S("abcde"), 1, S("1234567890"), 1, 4, S("a2345bcde"));
+    test(S("abcde"), 1, S("1234567890"), 1, 8, S("a23456789bcde"));
+    test(S("abcde"), 1, S("1234567890"), 1, 9, S("a234567890bcde"));
+    test(S("abcde"), 1, S("1234567890"), 1, 10, S("a234567890bcde"));
+    test(S("abcde"), 1, S("1234567890"), 5, 0, S("abcde"));
+    test(S("abcde"), 1, S("1234567890"), 5, 1, S("a6bcde"));
+    test(S("abcde"), 1, S("1234567890"), 5, 2, S("a67bcde"));
+    test(S("abcde"), 1, S("1234567890"), 5, 4, S("a6789bcde"));
+    test(S("abcde"), 1, S("1234567890"), 5, 5, S("a67890bcde"));
+    test(S("abcde"), 1, S("1234567890"), 5, 6, S("a67890bcde"));
+    test(S("abcde"), 1, S("1234567890"), 9, 0, S("abcde"));
+    test(S("abcde"), 1, S("1234567890"), 9, 1, S("a0bcde"));
+    test(S("abcde"), 1, S("1234567890"), 9, 2, S("a0bcde"));
+    test(S("abcde"), 1, S("1234567890"), 10, 0, S("abcde"));
+    test(S("abcde"), 1, S("1234567890"), 10, 1, S("abcde"));
+    test(S("abcde"), 1, S("1234567890"), 11, 0, S("can't happen"));
+    test(S("abcde"), 1, S("12345678901234567890"), 0, 0, S("abcde"));
+    test(S("abcde"), 1, S("12345678901234567890"), 0, 1, S("a1bcde"));
+    test(S("abcde"), 1, S("12345678901234567890"), 0, 10, S("a1234567890bcde"));
+    test(S("abcde"), 1, S("12345678901234567890"), 0, 19, S("a1234567890123456789bcde"));
+    test(S("abcde"), 1, S("12345678901234567890"), 0, 20, S("a12345678901234567890bcde"));
+    test(S("abcde"), 1, S("12345678901234567890"), 0, 21, S("a12345678901234567890bcde"));
+    test(S("abcde"), 1, S("12345678901234567890"), 1, 0, S("abcde"));
+    test(S("abcde"), 1, S("12345678901234567890"), 1, 1, S("a2bcde"));
+    test(S("abcde"), 1, S("12345678901234567890"), 1, 9, S("a234567890bcde"));
+    test(S("abcde"), 1, S("12345678901234567890"), 1, 18, S("a234567890123456789bcde"));
+    test(S("abcde"), 1, S("12345678901234567890"), 1, 19, S("a2345678901234567890bcde"));
+    test(S("abcde"), 1, S("12345678901234567890"), 1, 20, S("a2345678901234567890bcde"));
+    test(S("abcde"), 1, S("12345678901234567890"), 10, 0, S("abcde"));
+    test(S("abcde"), 1, S("12345678901234567890"), 10, 1, S("a1bcde"));
+    test(S("abcde"), 1, S("12345678901234567890"), 10, 5, S("a12345bcde"));
+    test(S("abcde"), 1, S("12345678901234567890"), 10, 9, S("a123456789bcde"));
+    test(S("abcde"), 1, S("12345678901234567890"), 10, 10, S("a1234567890bcde"));
+    test(S("abcde"), 1, S("12345678901234567890"), 10, 11, S("a1234567890bcde"));
+    test(S("abcde"), 1, S("12345678901234567890"), 19, 0, S("abcde"));
+    test(S("abcde"), 1, S("12345678901234567890"), 19, 1, S("a0bcde"));
+    test(S("abcde"), 1, S("12345678901234567890"), 19, 2, S("a0bcde"));
+    test(S("abcde"), 1, S("12345678901234567890"), 20, 0, S("abcde"));
+    test(S("abcde"), 1, S("12345678901234567890"), 20, 1, S("abcde"));
+    test(S("abcde"), 1, S("12345678901234567890"), 21, 0, S("can't happen"));
+    test(S("abcde"), 2, S(""), 0, 0, S("abcde"));
+    test(S("abcde"), 2, S(""), 0, 1, S("abcde"));
+    test(S("abcde"), 2, S(""), 1, 0, S("can't happen"));
+    test(S("abcde"), 2, S("12345"), 0, 0, S("abcde"));
+}
+
+void test6()
+{
+    test(S("abcde"), 2, S("12345"), 0, 1, S("ab1cde"));
+    test(S("abcde"), 2, S("12345"), 0, 2, S("ab12cde"));
+    test(S("abcde"), 2, S("12345"), 0, 4, S("ab1234cde"));
+    test(S("abcde"), 2, S("12345"), 0, 5, S("ab12345cde"));
+    test(S("abcde"), 2, S("12345"), 0, 6, S("ab12345cde"));
+    test(S("abcde"), 2, S("12345"), 1, 0, S("abcde"));
+    test(S("abcde"), 2, S("12345"), 1, 1, S("ab2cde"));
+    test(S("abcde"), 2, S("12345"), 1, 2, S("ab23cde"));
+    test(S("abcde"), 2, S("12345"), 1, 3, S("ab234cde"));
+    test(S("abcde"), 2, S("12345"), 1, 4, S("ab2345cde"));
+    test(S("abcde"), 2, S("12345"), 1, 5, S("ab2345cde"));
+    test(S("abcde"), 2, S("12345"), 2, 0, S("abcde"));
+    test(S("abcde"), 2, S("12345"), 2, 1, S("ab3cde"));
+    test(S("abcde"), 2, S("12345"), 2, 2, S("ab34cde"));
+    test(S("abcde"), 2, S("12345"), 2, 3, S("ab345cde"));
+    test(S("abcde"), 2, S("12345"), 2, 4, S("ab345cde"));
+    test(S("abcde"), 2, S("12345"), 4, 0, S("abcde"));
+    test(S("abcde"), 2, S("12345"), 4, 1, S("ab5cde"));
+    test(S("abcde"), 2, S("12345"), 4, 2, S("ab5cde"));
+    test(S("abcde"), 2, S("12345"), 5, 0, S("abcde"));
+    test(S("abcde"), 2, S("12345"), 5, 1, S("abcde"));
+    test(S("abcde"), 2, S("12345"), 6, 0, S("can't happen"));
+    test(S("abcde"), 2, S("1234567890"), 0, 0, S("abcde"));
+    test(S("abcde"), 2, S("1234567890"), 0, 1, S("ab1cde"));
+    test(S("abcde"), 2, S("1234567890"), 0, 5, S("ab12345cde"));
+    test(S("abcde"), 2, S("1234567890"), 0, 9, S("ab123456789cde"));
+    test(S("abcde"), 2, S("1234567890"), 0, 10, S("ab1234567890cde"));
+    test(S("abcde"), 2, S("1234567890"), 0, 11, S("ab1234567890cde"));
+    test(S("abcde"), 2, S("1234567890"), 1, 0, S("abcde"));
+    test(S("abcde"), 2, S("1234567890"), 1, 1, S("ab2cde"));
+    test(S("abcde"), 2, S("1234567890"), 1, 4, S("ab2345cde"));
+    test(S("abcde"), 2, S("1234567890"), 1, 8, S("ab23456789cde"));
+    test(S("abcde"), 2, S("1234567890"), 1, 9, S("ab234567890cde"));
+    test(S("abcde"), 2, S("1234567890"), 1, 10, S("ab234567890cde"));
+    test(S("abcde"), 2, S("1234567890"), 5, 0, S("abcde"));
+    test(S("abcde"), 2, S("1234567890"), 5, 1, S("ab6cde"));
+    test(S("abcde"), 2, S("1234567890"), 5, 2, S("ab67cde"));
+    test(S("abcde"), 2, S("1234567890"), 5, 4, S("ab6789cde"));
+    test(S("abcde"), 2, S("1234567890"), 5, 5, S("ab67890cde"));
+    test(S("abcde"), 2, S("1234567890"), 5, 6, S("ab67890cde"));
+    test(S("abcde"), 2, S("1234567890"), 9, 0, S("abcde"));
+    test(S("abcde"), 2, S("1234567890"), 9, 1, S("ab0cde"));
+    test(S("abcde"), 2, S("1234567890"), 9, 2, S("ab0cde"));
+    test(S("abcde"), 2, S("1234567890"), 10, 0, S("abcde"));
+    test(S("abcde"), 2, S("1234567890"), 10, 1, S("abcde"));
+    test(S("abcde"), 2, S("1234567890"), 11, 0, S("can't happen"));
+    test(S("abcde"), 2, S("12345678901234567890"), 0, 0, S("abcde"));
+    test(S("abcde"), 2, S("12345678901234567890"), 0, 1, S("ab1cde"));
+    test(S("abcde"), 2, S("12345678901234567890"), 0, 10, S("ab1234567890cde"));
+    test(S("abcde"), 2, S("12345678901234567890"), 0, 19, S("ab1234567890123456789cde"));
+}
+
+void test7()
+{
+    test(S("abcde"), 2, S("12345678901234567890"), 0, 20, S("ab12345678901234567890cde"));
+    test(S("abcde"), 2, S("12345678901234567890"), 0, 21, S("ab12345678901234567890cde"));
+    test(S("abcde"), 2, S("12345678901234567890"), 1, 0, S("abcde"));
+    test(S("abcde"), 2, S("12345678901234567890"), 1, 1, S("ab2cde"));
+    test(S("abcde"), 2, S("12345678901234567890"), 1, 9, S("ab234567890cde"));
+    test(S("abcde"), 2, S("12345678901234567890"), 1, 18, S("ab234567890123456789cde"));
+    test(S("abcde"), 2, S("12345678901234567890"), 1, 19, S("ab2345678901234567890cde"));
+    test(S("abcde"), 2, S("12345678901234567890"), 1, 20, S("ab2345678901234567890cde"));
+    test(S("abcde"), 2, S("12345678901234567890"), 10, 0, S("abcde"));
+    test(S("abcde"), 2, S("12345678901234567890"), 10, 1, S("ab1cde"));
+    test(S("abcde"), 2, S("12345678901234567890"), 10, 5, S("ab12345cde"));
+    test(S("abcde"), 2, S("12345678901234567890"), 10, 9, S("ab123456789cde"));
+    test(S("abcde"), 2, S("12345678901234567890"), 10, 10, S("ab1234567890cde"));
+    test(S("abcde"), 2, S("12345678901234567890"), 10, 11, S("ab1234567890cde"));
+    test(S("abcde"), 2, S("12345678901234567890"), 19, 0, S("abcde"));
+    test(S("abcde"), 2, S("12345678901234567890"), 19, 1, S("ab0cde"));
+    test(S("abcde"), 2, S("12345678901234567890"), 19, 2, S("ab0cde"));
+    test(S("abcde"), 2, S("12345678901234567890"), 20, 0, S("abcde"));
+    test(S("abcde"), 2, S("12345678901234567890"), 20, 1, S("abcde"));
+    test(S("abcde"), 2, S("12345678901234567890"), 21, 0, S("can't happen"));
+    test(S("abcde"), 4, S(""), 0, 0, S("abcde"));
+    test(S("abcde"), 4, S(""), 0, 1, S("abcde"));
+    test(S("abcde"), 4, S(""), 1, 0, S("can't happen"));
+    test(S("abcde"), 4, S("12345"), 0, 0, S("abcde"));
+    test(S("abcde"), 4, S("12345"), 0, 1, S("abcd1e"));
+    test(S("abcde"), 4, S("12345"), 0, 2, S("abcd12e"));
+    test(S("abcde"), 4, S("12345"), 0, 4, S("abcd1234e"));
+    test(S("abcde"), 4, S("12345"), 0, 5, S("abcd12345e"));
+    test(S("abcde"), 4, S("12345"), 0, 6, S("abcd12345e"));
+    test(S("abcde"), 4, S("12345"), 1, 0, S("abcde"));
+    test(S("abcde"), 4, S("12345"), 1, 1, S("abcd2e"));
+    test(S("abcde"), 4, S("12345"), 1, 2, S("abcd23e"));
+    test(S("abcde"), 4, S("12345"), 1, 3, S("abcd234e"));
+    test(S("abcde"), 4, S("12345"), 1, 4, S("abcd2345e"));
+    test(S("abcde"), 4, S("12345"), 1, 5, S("abcd2345e"));
+    test(S("abcde"), 4, S("12345"), 2, 0, S("abcde"));
+    test(S("abcde"), 4, S("12345"), 2, 1, S("abcd3e"));
+    test(S("abcde"), 4, S("12345"), 2, 2, S("abcd34e"));
+    test(S("abcde"), 4, S("12345"), 2, 3, S("abcd345e"));
+    test(S("abcde"), 4, S("12345"), 2, 4, S("abcd345e"));
+    test(S("abcde"), 4, S("12345"), 4, 0, S("abcde"));
+    test(S("abcde"), 4, S("12345"), 4, 1, S("abcd5e"));
+    test(S("abcde"), 4, S("12345"), 4, 2, S("abcd5e"));
+    test(S("abcde"), 4, S("12345"), 5, 0, S("abcde"));
+    test(S("abcde"), 4, S("12345"), 5, 1, S("abcde"));
+    test(S("abcde"), 4, S("12345"), 6, 0, S("can't happen"));
+    test(S("abcde"), 4, S("1234567890"), 0, 0, S("abcde"));
+    test(S("abcde"), 4, S("1234567890"), 0, 1, S("abcd1e"));
+    test(S("abcde"), 4, S("1234567890"), 0, 5, S("abcd12345e"));
+    test(S("abcde"), 4, S("1234567890"), 0, 9, S("abcd123456789e"));
+}
+
+void test8()
+{
+    test(S("abcde"), 4, S("1234567890"), 0, 10, S("abcd1234567890e"));
+    test(S("abcde"), 4, S("1234567890"), 0, 11, S("abcd1234567890e"));
+    test(S("abcde"), 4, S("1234567890"), 1, 0, S("abcde"));
+    test(S("abcde"), 4, S("1234567890"), 1, 1, S("abcd2e"));
+    test(S("abcde"), 4, S("1234567890"), 1, 4, S("abcd2345e"));
+    test(S("abcde"), 4, S("1234567890"), 1, 8, S("abcd23456789e"));
+    test(S("abcde"), 4, S("1234567890"), 1, 9, S("abcd234567890e"));
+    test(S("abcde"), 4, S("1234567890"), 1, 10, S("abcd234567890e"));
+    test(S("abcde"), 4, S("1234567890"), 5, 0, S("abcde"));
+    test(S("abcde"), 4, S("1234567890"), 5, 1, S("abcd6e"));
+    test(S("abcde"), 4, S("1234567890"), 5, 2, S("abcd67e"));
+    test(S("abcde"), 4, S("1234567890"), 5, 4, S("abcd6789e"));
+    test(S("abcde"), 4, S("1234567890"), 5, 5, S("abcd67890e"));
+    test(S("abcde"), 4, S("1234567890"), 5, 6, S("abcd67890e"));
+    test(S("abcde"), 4, S("1234567890"), 9, 0, S("abcde"));
+    test(S("abcde"), 4, S("1234567890"), 9, 1, S("abcd0e"));
+    test(S("abcde"), 4, S("1234567890"), 9, 2, S("abcd0e"));
+    test(S("abcde"), 4, S("1234567890"), 10, 0, S("abcde"));
+    test(S("abcde"), 4, S("1234567890"), 10, 1, S("abcde"));
+    test(S("abcde"), 4, S("1234567890"), 11, 0, S("can't happen"));
+    test(S("abcde"), 4, S("12345678901234567890"), 0, 0, S("abcde"));
+    test(S("abcde"), 4, S("12345678901234567890"), 0, 1, S("abcd1e"));
+    test(S("abcde"), 4, S("12345678901234567890"), 0, 10, S("abcd1234567890e"));
+    test(S("abcde"), 4, S("12345678901234567890"), 0, 19, S("abcd1234567890123456789e"));
+    test(S("abcde"), 4, S("12345678901234567890"), 0, 20, S("abcd12345678901234567890e"));
+    test(S("abcde"), 4, S("12345678901234567890"), 0, 21, S("abcd12345678901234567890e"));
+    test(S("abcde"), 4, S("12345678901234567890"), 1, 0, S("abcde"));
+    test(S("abcde"), 4, S("12345678901234567890"), 1, 1, S("abcd2e"));
+    test(S("abcde"), 4, S("12345678901234567890"), 1, 9, S("abcd234567890e"));
+    test(S("abcde"), 4, S("12345678901234567890"), 1, 18, S("abcd234567890123456789e"));
+    test(S("abcde"), 4, S("12345678901234567890"), 1, 19, S("abcd2345678901234567890e"));
+    test(S("abcde"), 4, S("12345678901234567890"), 1, 20, S("abcd2345678901234567890e"));
+    test(S("abcde"), 4, S("12345678901234567890"), 10, 0, S("abcde"));
+    test(S("abcde"), 4, S("12345678901234567890"), 10, 1, S("abcd1e"));
+    test(S("abcde"), 4, S("12345678901234567890"), 10, 5, S("abcd12345e"));
+    test(S("abcde"), 4, S("12345678901234567890"), 10, 9, S("abcd123456789e"));
+    test(S("abcde"), 4, S("12345678901234567890"), 10, 10, S("abcd1234567890e"));
+    test(S("abcde"), 4, S("12345678901234567890"), 10, 11, S("abcd1234567890e"));
+    test(S("abcde"), 4, S("12345678901234567890"), 19, 0, S("abcde"));
+    test(S("abcde"), 4, S("12345678901234567890"), 19, 1, S("abcd0e"));
+    test(S("abcde"), 4, S("12345678901234567890"), 19, 2, S("abcd0e"));
+    test(S("abcde"), 4, S("12345678901234567890"), 20, 0, S("abcde"));
+    test(S("abcde"), 4, S("12345678901234567890"), 20, 1, S("abcde"));
+    test(S("abcde"), 4, S("12345678901234567890"), 21, 0, S("can't happen"));
+    test(S("abcde"), 5, S(""), 0, 0, S("abcde"));
+    test(S("abcde"), 5, S(""), 0, 1, S("abcde"));
+    test(S("abcde"), 5, S(""), 1, 0, S("can't happen"));
+    test(S("abcde"), 5, S("12345"), 0, 0, S("abcde"));
+    test(S("abcde"), 5, S("12345"), 0, 1, S("abcde1"));
+    test(S("abcde"), 5, S("12345"), 0, 2, S("abcde12"));
+}
+
+void test9()
+{
+    test(S("abcde"), 5, S("12345"), 0, 4, S("abcde1234"));
+    test(S("abcde"), 5, S("12345"), 0, 5, S("abcde12345"));
+    test(S("abcde"), 5, S("12345"), 0, 6, S("abcde12345"));
+    test(S("abcde"), 5, S("12345"), 1, 0, S("abcde"));
+    test(S("abcde"), 5, S("12345"), 1, 1, S("abcde2"));
+    test(S("abcde"), 5, S("12345"), 1, 2, S("abcde23"));
+    test(S("abcde"), 5, S("12345"), 1, 3, S("abcde234"));
+    test(S("abcde"), 5, S("12345"), 1, 4, S("abcde2345"));
+    test(S("abcde"), 5, S("12345"), 1, 5, S("abcde2345"));
+    test(S("abcde"), 5, S("12345"), 2, 0, S("abcde"));
+    test(S("abcde"), 5, S("12345"), 2, 1, S("abcde3"));
+    test(S("abcde"), 5, S("12345"), 2, 2, S("abcde34"));
+    test(S("abcde"), 5, S("12345"), 2, 3, S("abcde345"));
+    test(S("abcde"), 5, S("12345"), 2, 4, S("abcde345"));
+    test(S("abcde"), 5, S("12345"), 4, 0, S("abcde"));
+    test(S("abcde"), 5, S("12345"), 4, 1, S("abcde5"));
+    test(S("abcde"), 5, S("12345"), 4, 2, S("abcde5"));
+    test(S("abcde"), 5, S("12345"), 5, 0, S("abcde"));
+    test(S("abcde"), 5, S("12345"), 5, 1, S("abcde"));
+    test(S("abcde"), 5, S("12345"), 6, 0, S("can't happen"));
+    test(S("abcde"), 5, S("1234567890"), 0, 0, S("abcde"));
+    test(S("abcde"), 5, S("1234567890"), 0, 1, S("abcde1"));
+    test(S("abcde"), 5, S("1234567890"), 0, 5, S("abcde12345"));
+    test(S("abcde"), 5, S("1234567890"), 0, 9, S("abcde123456789"));
+    test(S("abcde"), 5, S("1234567890"), 0, 10, S("abcde1234567890"));
+    test(S("abcde"), 5, S("1234567890"), 0, 11, S("abcde1234567890"));
+    test(S("abcde"), 5, S("1234567890"), 1, 0, S("abcde"));
+    test(S("abcde"), 5, S("1234567890"), 1, 1, S("abcde2"));
+    test(S("abcde"), 5, S("1234567890"), 1, 4, S("abcde2345"));
+    test(S("abcde"), 5, S("1234567890"), 1, 8, S("abcde23456789"));
+    test(S("abcde"), 5, S("1234567890"), 1, 9, S("abcde234567890"));
+    test(S("abcde"), 5, S("1234567890"), 1, 10, S("abcde234567890"));
+    test(S("abcde"), 5, S("1234567890"), 5, 0, S("abcde"));
+    test(S("abcde"), 5, S("1234567890"), 5, 1, S("abcde6"));
+    test(S("abcde"), 5, S("1234567890"), 5, 2, S("abcde67"));
+    test(S("abcde"), 5, S("1234567890"), 5, 4, S("abcde6789"));
+    test(S("abcde"), 5, S("1234567890"), 5, 5, S("abcde67890"));
+    test(S("abcde"), 5, S("1234567890"), 5, 6, S("abcde67890"));
+    test(S("abcde"), 5, S("1234567890"), 9, 0, S("abcde"));
+    test(S("abcde"), 5, S("1234567890"), 9, 1, S("abcde0"));
+    test(S("abcde"), 5, S("1234567890"), 9, 2, S("abcde0"));
+    test(S("abcde"), 5, S("1234567890"), 10, 0, S("abcde"));
+    test(S("abcde"), 5, S("1234567890"), 10, 1, S("abcde"));
+    test(S("abcde"), 5, S("1234567890"), 11, 0, S("can't happen"));
+    test(S("abcde"), 5, S("12345678901234567890"), 0, 0, S("abcde"));
+    test(S("abcde"), 5, S("12345678901234567890"), 0, 1, S("abcde1"));
+    test(S("abcde"), 5, S("12345678901234567890"), 0, 10, S("abcde1234567890"));
+    test(S("abcde"), 5, S("12345678901234567890"), 0, 19, S("abcde1234567890123456789"));
+    test(S("abcde"), 5, S("12345678901234567890"), 0, 20, S("abcde12345678901234567890"));
+    test(S("abcde"), 5, S("12345678901234567890"), 0, 21, S("abcde12345678901234567890"));
+}
+
+void test10()
+{
+    test(S("abcde"), 5, S("12345678901234567890"), 1, 0, S("abcde"));
+    test(S("abcde"), 5, S("12345678901234567890"), 1, 1, S("abcde2"));
+    test(S("abcde"), 5, S("12345678901234567890"), 1, 9, S("abcde234567890"));
+    test(S("abcde"), 5, S("12345678901234567890"), 1, 18, S("abcde234567890123456789"));
+    test(S("abcde"), 5, S("12345678901234567890"), 1, 19, S("abcde2345678901234567890"));
+    test(S("abcde"), 5, S("12345678901234567890"), 1, 20, S("abcde2345678901234567890"));
+    test(S("abcde"), 5, S("12345678901234567890"), 10, 0, S("abcde"));
+    test(S("abcde"), 5, S("12345678901234567890"), 10, 1, S("abcde1"));
+    test(S("abcde"), 5, S("12345678901234567890"), 10, 5, S("abcde12345"));
+    test(S("abcde"), 5, S("12345678901234567890"), 10, 9, S("abcde123456789"));
+    test(S("abcde"), 5, S("12345678901234567890"), 10, 10, S("abcde1234567890"));
+    test(S("abcde"), 5, S("12345678901234567890"), 10, 11, S("abcde1234567890"));
+    test(S("abcde"), 5, S("12345678901234567890"), 19, 0, S("abcde"));
+    test(S("abcde"), 5, S("12345678901234567890"), 19, 1, S("abcde0"));
+    test(S("abcde"), 5, S("12345678901234567890"), 19, 2, S("abcde0"));
+    test(S("abcde"), 5, S("12345678901234567890"), 20, 0, S("abcde"));
+    test(S("abcde"), 5, S("12345678901234567890"), 20, 1, S("abcde"));
+    test(S("abcde"), 5, S("12345678901234567890"), 21, 0, S("can't happen"));
+    test(S("abcde"), 6, S(""), 0, 0, S("can't happen"));
+    test(S("abcde"), 6, S(""), 0, 1, S("can't happen"));
+    test(S("abcde"), 6, S(""), 1, 0, S("can't happen"));
+    test(S("abcde"), 6, S("12345"), 0, 0, S("can't happen"));
+    test(S("abcde"), 6, S("12345"), 0, 1, S("can't happen"));
+    test(S("abcde"), 6, S("12345"), 0, 2, S("can't happen"));
+    test(S("abcde"), 6, S("12345"), 0, 4, S("can't happen"));
+    test(S("abcde"), 6, S("12345"), 0, 5, S("can't happen"));
+    test(S("abcde"), 6, S("12345"), 0, 6, S("can't happen"));
+    test(S("abcde"), 6, S("12345"), 1, 0, S("can't happen"));
+    test(S("abcde"), 6, S("12345"), 1, 1, S("can't happen"));
+    test(S("abcde"), 6, S("12345"), 1, 2, S("can't happen"));
+    test(S("abcde"), 6, S("12345"), 1, 3, S("can't happen"));
+    test(S("abcde"), 6, S("12345"), 1, 4, S("can't happen"));
+    test(S("abcde"), 6, S("12345"), 1, 5, S("can't happen"));
+    test(S("abcde"), 6, S("12345"), 2, 0, S("can't happen"));
+    test(S("abcde"), 6, S("12345"), 2, 1, S("can't happen"));
+    test(S("abcde"), 6, S("12345"), 2, 2, S("can't happen"));
+    test(S("abcde"), 6, S("12345"), 2, 3, S("can't happen"));
+    test(S("abcde"), 6, S("12345"), 2, 4, S("can't happen"));
+    test(S("abcde"), 6, S("12345"), 4, 0, S("can't happen"));
+    test(S("abcde"), 6, S("12345"), 4, 1, S("can't happen"));
+    test(S("abcde"), 6, S("12345"), 4, 2, S("can't happen"));
+    test(S("abcde"), 6, S("12345"), 5, 0, S("can't happen"));
+    test(S("abcde"), 6, S("12345"), 5, 1, S("can't happen"));
+    test(S("abcde"), 6, S("12345"), 6, 0, S("can't happen"));
+    test(S("abcde"), 6, S("1234567890"), 0, 0, S("can't happen"));
+    test(S("abcde"), 6, S("1234567890"), 0, 1, S("can't happen"));
+    test(S("abcde"), 6, S("1234567890"), 0, 5, S("can't happen"));
+    test(S("abcde"), 6, S("1234567890"), 0, 9, S("can't happen"));
+    test(S("abcde"), 6, S("1234567890"), 0, 10, S("can't happen"));
+    test(S("abcde"), 6, S("1234567890"), 0, 11, S("can't happen"));
+}
+
+void test11()
+{
+    test(S("abcde"), 6, S("1234567890"), 1, 0, S("can't happen"));
+    test(S("abcde"), 6, S("1234567890"), 1, 1, S("can't happen"));
+    test(S("abcde"), 6, S("1234567890"), 1, 4, S("can't happen"));
+    test(S("abcde"), 6, S("1234567890"), 1, 8, S("can't happen"));
+    test(S("abcde"), 6, S("1234567890"), 1, 9, S("can't happen"));
+    test(S("abcde"), 6, S("1234567890"), 1, 10, S("can't happen"));
+    test(S("abcde"), 6, S("1234567890"), 5, 0, S("can't happen"));
+    test(S("abcde"), 6, S("1234567890"), 5, 1, S("can't happen"));
+    test(S("abcde"), 6, S("1234567890"), 5, 2, S("can't happen"));
+    test(S("abcde"), 6, S("1234567890"), 5, 4, S("can't happen"));
+    test(S("abcde"), 6, S("1234567890"), 5, 5, S("can't happen"));
+    test(S("abcde"), 6, S("1234567890"), 5, 6, S("can't happen"));
+    test(S("abcde"), 6, S("1234567890"), 9, 0, S("can't happen"));
+    test(S("abcde"), 6, S("1234567890"), 9, 1, S("can't happen"));
+    test(S("abcde"), 6, S("1234567890"), 9, 2, S("can't happen"));
+    test(S("abcde"), 6, S("1234567890"), 10, 0, S("can't happen"));
+    test(S("abcde"), 6, S("1234567890"), 10, 1, S("can't happen"));
+    test(S("abcde"), 6, S("1234567890"), 11, 0, S("can't happen"));
+    test(S("abcde"), 6, S("12345678901234567890"), 0, 0, S("can't happen"));
+    test(S("abcde"), 6, S("12345678901234567890"), 0, 1, S("can't happen"));
+    test(S("abcde"), 6, S("12345678901234567890"), 0, 10, S("can't happen"));
+    test(S("abcde"), 6, S("12345678901234567890"), 0, 19, S("can't happen"));
+    test(S("abcde"), 6, S("12345678901234567890"), 0, 20, S("can't happen"));
+    test(S("abcde"), 6, S("12345678901234567890"), 0, 21, S("can't happen"));
+    test(S("abcde"), 6, S("12345678901234567890"), 1, 0, S("can't happen"));
+    test(S("abcde"), 6, S("12345678901234567890"), 1, 1, S("can't happen"));
+    test(S("abcde"), 6, S("12345678901234567890"), 1, 9, S("can't happen"));
+    test(S("abcde"), 6, S("12345678901234567890"), 1, 18, S("can't happen"));
+    test(S("abcde"), 6, S("12345678901234567890"), 1, 19, S("can't happen"));
+    test(S("abcde"), 6, S("12345678901234567890"), 1, 20, S("can't happen"));
+    test(S("abcde"), 6, S("12345678901234567890"), 10, 0, S("can't happen"));
+    test(S("abcde"), 6, S("12345678901234567890"), 10, 1, S("can't happen"));
+    test(S("abcde"), 6, S("12345678901234567890"), 10, 5, S("can't happen"));
+    test(S("abcde"), 6, S("12345678901234567890"), 10, 9, S("can't happen"));
+    test(S("abcde"), 6, S("12345678901234567890"), 10, 10, S("can't happen"));
+    test(S("abcde"), 6, S("12345678901234567890"), 10, 11, S("can't happen"));
+    test(S("abcde"), 6, S("12345678901234567890"), 19, 0, S("can't happen"));
+    test(S("abcde"), 6, S("12345678901234567890"), 19, 1, S("can't happen"));
+    test(S("abcde"), 6, S("12345678901234567890"), 19, 2, S("can't happen"));
+    test(S("abcde"), 6, S("12345678901234567890"), 20, 0, S("can't happen"));
+    test(S("abcde"), 6, S("12345678901234567890"), 20, 1, S("can't happen"));
+    test(S("abcde"), 6, S("12345678901234567890"), 21, 0, S("can't happen"));
+    test(S("abcdefghij"), 0, S(""), 0, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 0, S(""), 0, 1, S("abcdefghij"));
+    test(S("abcdefghij"), 0, S(""), 1, 0, S("can't happen"));
+    test(S("abcdefghij"), 0, S("12345"), 0, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 0, S("12345"), 0, 1, S("1abcdefghij"));
+    test(S("abcdefghij"), 0, S("12345"), 0, 2, S("12abcdefghij"));
+    test(S("abcdefghij"), 0, S("12345"), 0, 4, S("1234abcdefghij"));
+    test(S("abcdefghij"), 0, S("12345"), 0, 5, S("12345abcdefghij"));
+}
+
+void test12()
+{
+    test(S("abcdefghij"), 0, S("12345"), 0, 6, S("12345abcdefghij"));
+    test(S("abcdefghij"), 0, S("12345"), 1, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 0, S("12345"), 1, 1, S("2abcdefghij"));
+    test(S("abcdefghij"), 0, S("12345"), 1, 2, S("23abcdefghij"));
+    test(S("abcdefghij"), 0, S("12345"), 1, 3, S("234abcdefghij"));
+    test(S("abcdefghij"), 0, S("12345"), 1, 4, S("2345abcdefghij"));
+    test(S("abcdefghij"), 0, S("12345"), 1, 5, S("2345abcdefghij"));
+    test(S("abcdefghij"), 0, S("12345"), 2, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 0, S("12345"), 2, 1, S("3abcdefghij"));
+    test(S("abcdefghij"), 0, S("12345"), 2, 2, S("34abcdefghij"));
+    test(S("abcdefghij"), 0, S("12345"), 2, 3, S("345abcdefghij"));
+    test(S("abcdefghij"), 0, S("12345"), 2, 4, S("345abcdefghij"));
+    test(S("abcdefghij"), 0, S("12345"), 4, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 0, S("12345"), 4, 1, S("5abcdefghij"));
+    test(S("abcdefghij"), 0, S("12345"), 4, 2, S("5abcdefghij"));
+    test(S("abcdefghij"), 0, S("12345"), 5, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 0, S("12345"), 5, 1, S("abcdefghij"));
+    test(S("abcdefghij"), 0, S("12345"), 6, 0, S("can't happen"));
+    test(S("abcdefghij"), 0, S("1234567890"), 0, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 0, S("1234567890"), 0, 1, S("1abcdefghij"));
+    test(S("abcdefghij"), 0, S("1234567890"), 0, 5, S("12345abcdefghij"));
+    test(S("abcdefghij"), 0, S("1234567890"), 0, 9, S("123456789abcdefghij"));
+    test(S("abcdefghij"), 0, S("1234567890"), 0, 10, S("1234567890abcdefghij"));
+    test(S("abcdefghij"), 0, S("1234567890"), 0, 11, S("1234567890abcdefghij"));
+    test(S("abcdefghij"), 0, S("1234567890"), 1, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 0, S("1234567890"), 1, 1, S("2abcdefghij"));
+    test(S("abcdefghij"), 0, S("1234567890"), 1, 4, S("2345abcdefghij"));
+    test(S("abcdefghij"), 0, S("1234567890"), 1, 8, S("23456789abcdefghij"));
+    test(S("abcdefghij"), 0, S("1234567890"), 1, 9, S("234567890abcdefghij"));
+    test(S("abcdefghij"), 0, S("1234567890"), 1, 10, S("234567890abcdefghij"));
+    test(S("abcdefghij"), 0, S("1234567890"), 5, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 0, S("1234567890"), 5, 1, S("6abcdefghij"));
+    test(S("abcdefghij"), 0, S("1234567890"), 5, 2, S("67abcdefghij"));
+    test(S("abcdefghij"), 0, S("1234567890"), 5, 4, S("6789abcdefghij"));
+    test(S("abcdefghij"), 0, S("1234567890"), 5, 5, S("67890abcdefghij"));
+    test(S("abcdefghij"), 0, S("1234567890"), 5, 6, S("67890abcdefghij"));
+    test(S("abcdefghij"), 0, S("1234567890"), 9, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 0, S("1234567890"), 9, 1, S("0abcdefghij"));
+    test(S("abcdefghij"), 0, S("1234567890"), 9, 2, S("0abcdefghij"));
+    test(S("abcdefghij"), 0, S("1234567890"), 10, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 0, S("1234567890"), 10, 1, S("abcdefghij"));
+    test(S("abcdefghij"), 0, S("1234567890"), 11, 0, S("can't happen"));
+    test(S("abcdefghij"), 0, S("12345678901234567890"), 0, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 0, S("12345678901234567890"), 0, 1, S("1abcdefghij"));
+    test(S("abcdefghij"), 0, S("12345678901234567890"), 0, 10, S("1234567890abcdefghij"));
+    test(S("abcdefghij"), 0, S("12345678901234567890"), 0, 19, S("1234567890123456789abcdefghij"));
+    test(S("abcdefghij"), 0, S("12345678901234567890"), 0, 20, S("12345678901234567890abcdefghij"));
+    test(S("abcdefghij"), 0, S("12345678901234567890"), 0, 21, S("12345678901234567890abcdefghij"));
+    test(S("abcdefghij"), 0, S("12345678901234567890"), 1, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 0, S("12345678901234567890"), 1, 1, S("2abcdefghij"));
+}
+
+void test13()
+{
+    test(S("abcdefghij"), 0, S("12345678901234567890"), 1, 9, S("234567890abcdefghij"));
+    test(S("abcdefghij"), 0, S("12345678901234567890"), 1, 18, S("234567890123456789abcdefghij"));
+    test(S("abcdefghij"), 0, S("12345678901234567890"), 1, 19, S("2345678901234567890abcdefghij"));
+    test(S("abcdefghij"), 0, S("12345678901234567890"), 1, 20, S("2345678901234567890abcdefghij"));
+    test(S("abcdefghij"), 0, S("12345678901234567890"), 10, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 0, S("12345678901234567890"), 10, 1, S("1abcdefghij"));
+    test(S("abcdefghij"), 0, S("12345678901234567890"), 10, 5, S("12345abcdefghij"));
+    test(S("abcdefghij"), 0, S("12345678901234567890"), 10, 9, S("123456789abcdefghij"));
+    test(S("abcdefghij"), 0, S("12345678901234567890"), 10, 10, S("1234567890abcdefghij"));
+    test(S("abcdefghij"), 0, S("12345678901234567890"), 10, 11, S("1234567890abcdefghij"));
+    test(S("abcdefghij"), 0, S("12345678901234567890"), 19, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 0, S("12345678901234567890"), 19, 1, S("0abcdefghij"));
+    test(S("abcdefghij"), 0, S("12345678901234567890"), 19, 2, S("0abcdefghij"));
+    test(S("abcdefghij"), 0, S("12345678901234567890"), 20, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 0, S("12345678901234567890"), 20, 1, S("abcdefghij"));
+    test(S("abcdefghij"), 0, S("12345678901234567890"), 21, 0, S("can't happen"));
+    test(S("abcdefghij"), 1, S(""), 0, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 1, S(""), 0, 1, S("abcdefghij"));
+    test(S("abcdefghij"), 1, S(""), 1, 0, S("can't happen"));
+    test(S("abcdefghij"), 1, S("12345"), 0, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 1, S("12345"), 0, 1, S("a1bcdefghij"));
+    test(S("abcdefghij"), 1, S("12345"), 0, 2, S("a12bcdefghij"));
+    test(S("abcdefghij"), 1, S("12345"), 0, 4, S("a1234bcdefghij"));
+    test(S("abcdefghij"), 1, S("12345"), 0, 5, S("a12345bcdefghij"));
+    test(S("abcdefghij"), 1, S("12345"), 0, 6, S("a12345bcdefghij"));
+    test(S("abcdefghij"), 1, S("12345"), 1, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 1, S("12345"), 1, 1, S("a2bcdefghij"));
+    test(S("abcdefghij"), 1, S("12345"), 1, 2, S("a23bcdefghij"));
+    test(S("abcdefghij"), 1, S("12345"), 1, 3, S("a234bcdefghij"));
+    test(S("abcdefghij"), 1, S("12345"), 1, 4, S("a2345bcdefghij"));
+    test(S("abcdefghij"), 1, S("12345"), 1, 5, S("a2345bcdefghij"));
+    test(S("abcdefghij"), 1, S("12345"), 2, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 1, S("12345"), 2, 1, S("a3bcdefghij"));
+    test(S("abcdefghij"), 1, S("12345"), 2, 2, S("a34bcdefghij"));
+    test(S("abcdefghij"), 1, S("12345"), 2, 3, S("a345bcdefghij"));
+    test(S("abcdefghij"), 1, S("12345"), 2, 4, S("a345bcdefghij"));
+    test(S("abcdefghij"), 1, S("12345"), 4, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 1, S("12345"), 4, 1, S("a5bcdefghij"));
+    test(S("abcdefghij"), 1, S("12345"), 4, 2, S("a5bcdefghij"));
+    test(S("abcdefghij"), 1, S("12345"), 5, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 1, S("12345"), 5, 1, S("abcdefghij"));
+    test(S("abcdefghij"), 1, S("12345"), 6, 0, S("can't happen"));
+    test(S("abcdefghij"), 1, S("1234567890"), 0, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 1, S("1234567890"), 0, 1, S("a1bcdefghij"));
+    test(S("abcdefghij"), 1, S("1234567890"), 0, 5, S("a12345bcdefghij"));
+    test(S("abcdefghij"), 1, S("1234567890"), 0, 9, S("a123456789bcdefghij"));
+    test(S("abcdefghij"), 1, S("1234567890"), 0, 10, S("a1234567890bcdefghij"));
+    test(S("abcdefghij"), 1, S("1234567890"), 0, 11, S("a1234567890bcdefghij"));
+    test(S("abcdefghij"), 1, S("1234567890"), 1, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 1, S("1234567890"), 1, 1, S("a2bcdefghij"));
+}
+
+void test14()
+{
+    test(S("abcdefghij"), 1, S("1234567890"), 1, 4, S("a2345bcdefghij"));
+    test(S("abcdefghij"), 1, S("1234567890"), 1, 8, S("a23456789bcdefghij"));
+    test(S("abcdefghij"), 1, S("1234567890"), 1, 9, S("a234567890bcdefghij"));
+    test(S("abcdefghij"), 1, S("1234567890"), 1, 10, S("a234567890bcdefghij"));
+    test(S("abcdefghij"), 1, S("1234567890"), 5, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 1, S("1234567890"), 5, 1, S("a6bcdefghij"));
+    test(S("abcdefghij"), 1, S("1234567890"), 5, 2, S("a67bcdefghij"));
+    test(S("abcdefghij"), 1, S("1234567890"), 5, 4, S("a6789bcdefghij"));
+    test(S("abcdefghij"), 1, S("1234567890"), 5, 5, S("a67890bcdefghij"));
+    test(S("abcdefghij"), 1, S("1234567890"), 5, 6, S("a67890bcdefghij"));
+    test(S("abcdefghij"), 1, S("1234567890"), 9, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 1, S("1234567890"), 9, 1, S("a0bcdefghij"));
+    test(S("abcdefghij"), 1, S("1234567890"), 9, 2, S("a0bcdefghij"));
+    test(S("abcdefghij"), 1, S("1234567890"), 10, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 1, S("1234567890"), 10, 1, S("abcdefghij"));
+    test(S("abcdefghij"), 1, S("1234567890"), 11, 0, S("can't happen"));
+    test(S("abcdefghij"), 1, S("12345678901234567890"), 0, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 1, S("12345678901234567890"), 0, 1, S("a1bcdefghij"));
+    test(S("abcdefghij"), 1, S("12345678901234567890"), 0, 10, S("a1234567890bcdefghij"));
+    test(S("abcdefghij"), 1, S("12345678901234567890"), 0, 19, S("a1234567890123456789bcdefghij"));
+    test(S("abcdefghij"), 1, S("12345678901234567890"), 0, 20, S("a12345678901234567890bcdefghij"));
+    test(S("abcdefghij"), 1, S("12345678901234567890"), 0, 21, S("a12345678901234567890bcdefghij"));
+    test(S("abcdefghij"), 1, S("12345678901234567890"), 1, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 1, S("12345678901234567890"), 1, 1, S("a2bcdefghij"));
+    test(S("abcdefghij"), 1, S("12345678901234567890"), 1, 9, S("a234567890bcdefghij"));
+    test(S("abcdefghij"), 1, S("12345678901234567890"), 1, 18, S("a234567890123456789bcdefghij"));
+    test(S("abcdefghij"), 1, S("12345678901234567890"), 1, 19, S("a2345678901234567890bcdefghij"));
+    test(S("abcdefghij"), 1, S("12345678901234567890"), 1, 20, S("a2345678901234567890bcdefghij"));
+    test(S("abcdefghij"), 1, S("12345678901234567890"), 10, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 1, S("12345678901234567890"), 10, 1, S("a1bcdefghij"));
+    test(S("abcdefghij"), 1, S("12345678901234567890"), 10, 5, S("a12345bcdefghij"));
+    test(S("abcdefghij"), 1, S("12345678901234567890"), 10, 9, S("a123456789bcdefghij"));
+    test(S("abcdefghij"), 1, S("12345678901234567890"), 10, 10, S("a1234567890bcdefghij"));
+    test(S("abcdefghij"), 1, S("12345678901234567890"), 10, 11, S("a1234567890bcdefghij"));
+    test(S("abcdefghij"), 1, S("12345678901234567890"), 19, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 1, S("12345678901234567890"), 19, 1, S("a0bcdefghij"));
+    test(S("abcdefghij"), 1, S("12345678901234567890"), 19, 2, S("a0bcdefghij"));
+    test(S("abcdefghij"), 1, S("12345678901234567890"), 20, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 1, S("12345678901234567890"), 20, 1, S("abcdefghij"));
+    test(S("abcdefghij"), 1, S("12345678901234567890"), 21, 0, S("can't happen"));
+    test(S("abcdefghij"), 5, S(""), 0, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 5, S(""), 0, 1, S("abcdefghij"));
+    test(S("abcdefghij"), 5, S(""), 1, 0, S("can't happen"));
+    test(S("abcdefghij"), 5, S("12345"), 0, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 5, S("12345"), 0, 1, S("abcde1fghij"));
+    test(S("abcdefghij"), 5, S("12345"), 0, 2, S("abcde12fghij"));
+    test(S("abcdefghij"), 5, S("12345"), 0, 4, S("abcde1234fghij"));
+    test(S("abcdefghij"), 5, S("12345"), 0, 5, S("abcde12345fghij"));
+    test(S("abcdefghij"), 5, S("12345"), 0, 6, S("abcde12345fghij"));
+    test(S("abcdefghij"), 5, S("12345"), 1, 0, S("abcdefghij"));
+}
+
+void test15()
+{
+    test(S("abcdefghij"), 5, S("12345"), 1, 1, S("abcde2fghij"));
+    test(S("abcdefghij"), 5, S("12345"), 1, 2, S("abcde23fghij"));
+    test(S("abcdefghij"), 5, S("12345"), 1, 3, S("abcde234fghij"));
+    test(S("abcdefghij"), 5, S("12345"), 1, 4, S("abcde2345fghij"));
+    test(S("abcdefghij"), 5, S("12345"), 1, 5, S("abcde2345fghij"));
+    test(S("abcdefghij"), 5, S("12345"), 2, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 5, S("12345"), 2, 1, S("abcde3fghij"));
+    test(S("abcdefghij"), 5, S("12345"), 2, 2, S("abcde34fghij"));
+    test(S("abcdefghij"), 5, S("12345"), 2, 3, S("abcde345fghij"));
+    test(S("abcdefghij"), 5, S("12345"), 2, 4, S("abcde345fghij"));
+    test(S("abcdefghij"), 5, S("12345"), 4, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 5, S("12345"), 4, 1, S("abcde5fghij"));
+    test(S("abcdefghij"), 5, S("12345"), 4, 2, S("abcde5fghij"));
+    test(S("abcdefghij"), 5, S("12345"), 5, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 5, S("12345"), 5, 1, S("abcdefghij"));
+    test(S("abcdefghij"), 5, S("12345"), 6, 0, S("can't happen"));
+    test(S("abcdefghij"), 5, S("1234567890"), 0, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 5, S("1234567890"), 0, 1, S("abcde1fghij"));
+    test(S("abcdefghij"), 5, S("1234567890"), 0, 5, S("abcde12345fghij"));
+    test(S("abcdefghij"), 5, S("1234567890"), 0, 9, S("abcde123456789fghij"));
+    test(S("abcdefghij"), 5, S("1234567890"), 0, 10, S("abcde1234567890fghij"));
+    test(S("abcdefghij"), 5, S("1234567890"), 0, 11, S("abcde1234567890fghij"));
+    test(S("abcdefghij"), 5, S("1234567890"), 1, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 5, S("1234567890"), 1, 1, S("abcde2fghij"));
+    test(S("abcdefghij"), 5, S("1234567890"), 1, 4, S("abcde2345fghij"));
+    test(S("abcdefghij"), 5, S("1234567890"), 1, 8, S("abcde23456789fghij"));
+    test(S("abcdefghij"), 5, S("1234567890"), 1, 9, S("abcde234567890fghij"));
+    test(S("abcdefghij"), 5, S("1234567890"), 1, 10, S("abcde234567890fghij"));
+    test(S("abcdefghij"), 5, S("1234567890"), 5, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 5, S("1234567890"), 5, 1, S("abcde6fghij"));
+    test(S("abcdefghij"), 5, S("1234567890"), 5, 2, S("abcde67fghij"));
+    test(S("abcdefghij"), 5, S("1234567890"), 5, 4, S("abcde6789fghij"));
+    test(S("abcdefghij"), 5, S("1234567890"), 5, 5, S("abcde67890fghij"));
+    test(S("abcdefghij"), 5, S("1234567890"), 5, 6, S("abcde67890fghij"));
+    test(S("abcdefghij"), 5, S("1234567890"), 9, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 5, S("1234567890"), 9, 1, S("abcde0fghij"));
+    test(S("abcdefghij"), 5, S("1234567890"), 9, 2, S("abcde0fghij"));
+    test(S("abcdefghij"), 5, S("1234567890"), 10, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 5, S("1234567890"), 10, 1, S("abcdefghij"));
+    test(S("abcdefghij"), 5, S("1234567890"), 11, 0, S("can't happen"));
+    test(S("abcdefghij"), 5, S("12345678901234567890"), 0, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 5, S("12345678901234567890"), 0, 1, S("abcde1fghij"));
+    test(S("abcdefghij"), 5, S("12345678901234567890"), 0, 10, S("abcde1234567890fghij"));
+    test(S("abcdefghij"), 5, S("12345678901234567890"), 0, 19, S("abcde1234567890123456789fghij"));
+    test(S("abcdefghij"), 5, S("12345678901234567890"), 0, 20, S("abcde12345678901234567890fghij"));
+    test(S("abcdefghij"), 5, S("12345678901234567890"), 0, 21, S("abcde12345678901234567890fghij"));
+    test(S("abcdefghij"), 5, S("12345678901234567890"), 1, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 5, S("12345678901234567890"), 1, 1, S("abcde2fghij"));
+    test(S("abcdefghij"), 5, S("12345678901234567890"), 1, 9, S("abcde234567890fghij"));
+    test(S("abcdefghij"), 5, S("12345678901234567890"), 1, 18, S("abcde234567890123456789fghij"));
+}
+
+void test16()
+{
+    test(S("abcdefghij"), 5, S("12345678901234567890"), 1, 19, S("abcde2345678901234567890fghij"));
+    test(S("abcdefghij"), 5, S("12345678901234567890"), 1, 20, S("abcde2345678901234567890fghij"));
+    test(S("abcdefghij"), 5, S("12345678901234567890"), 10, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 5, S("12345678901234567890"), 10, 1, S("abcde1fghij"));
+    test(S("abcdefghij"), 5, S("12345678901234567890"), 10, 5, S("abcde12345fghij"));
+    test(S("abcdefghij"), 5, S("12345678901234567890"), 10, 9, S("abcde123456789fghij"));
+    test(S("abcdefghij"), 5, S("12345678901234567890"), 10, 10, S("abcde1234567890fghij"));
+    test(S("abcdefghij"), 5, S("12345678901234567890"), 10, 11, S("abcde1234567890fghij"));
+    test(S("abcdefghij"), 5, S("12345678901234567890"), 19, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 5, S("12345678901234567890"), 19, 1, S("abcde0fghij"));
+    test(S("abcdefghij"), 5, S("12345678901234567890"), 19, 2, S("abcde0fghij"));
+    test(S("abcdefghij"), 5, S("12345678901234567890"), 20, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 5, S("12345678901234567890"), 20, 1, S("abcdefghij"));
+    test(S("abcdefghij"), 5, S("12345678901234567890"), 21, 0, S("can't happen"));
+    test(S("abcdefghij"), 9, S(""), 0, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 9, S(""), 0, 1, S("abcdefghij"));
+    test(S("abcdefghij"), 9, S(""), 1, 0, S("can't happen"));
+    test(S("abcdefghij"), 9, S("12345"), 0, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 9, S("12345"), 0, 1, S("abcdefghi1j"));
+    test(S("abcdefghij"), 9, S("12345"), 0, 2, S("abcdefghi12j"));
+    test(S("abcdefghij"), 9, S("12345"), 0, 4, S("abcdefghi1234j"));
+    test(S("abcdefghij"), 9, S("12345"), 0, 5, S("abcdefghi12345j"));
+    test(S("abcdefghij"), 9, S("12345"), 0, 6, S("abcdefghi12345j"));
+    test(S("abcdefghij"), 9, S("12345"), 1, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 9, S("12345"), 1, 1, S("abcdefghi2j"));
+    test(S("abcdefghij"), 9, S("12345"), 1, 2, S("abcdefghi23j"));
+    test(S("abcdefghij"), 9, S("12345"), 1, 3, S("abcdefghi234j"));
+    test(S("abcdefghij"), 9, S("12345"), 1, 4, S("abcdefghi2345j"));
+    test(S("abcdefghij"), 9, S("12345"), 1, 5, S("abcdefghi2345j"));
+    test(S("abcdefghij"), 9, S("12345"), 2, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 9, S("12345"), 2, 1, S("abcdefghi3j"));
+    test(S("abcdefghij"), 9, S("12345"), 2, 2, S("abcdefghi34j"));
+    test(S("abcdefghij"), 9, S("12345"), 2, 3, S("abcdefghi345j"));
+    test(S("abcdefghij"), 9, S("12345"), 2, 4, S("abcdefghi345j"));
+    test(S("abcdefghij"), 9, S("12345"), 4, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 9, S("12345"), 4, 1, S("abcdefghi5j"));
+    test(S("abcdefghij"), 9, S("12345"), 4, 2, S("abcdefghi5j"));
+    test(S("abcdefghij"), 9, S("12345"), 5, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 9, S("12345"), 5, 1, S("abcdefghij"));
+    test(S("abcdefghij"), 9, S("12345"), 6, 0, S("can't happen"));
+    test(S("abcdefghij"), 9, S("1234567890"), 0, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 9, S("1234567890"), 0, 1, S("abcdefghi1j"));
+    test(S("abcdefghij"), 9, S("1234567890"), 0, 5, S("abcdefghi12345j"));
+    test(S("abcdefghij"), 9, S("1234567890"), 0, 9, S("abcdefghi123456789j"));
+    test(S("abcdefghij"), 9, S("1234567890"), 0, 10, S("abcdefghi1234567890j"));
+    test(S("abcdefghij"), 9, S("1234567890"), 0, 11, S("abcdefghi1234567890j"));
+    test(S("abcdefghij"), 9, S("1234567890"), 1, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 9, S("1234567890"), 1, 1, S("abcdefghi2j"));
+    test(S("abcdefghij"), 9, S("1234567890"), 1, 4, S("abcdefghi2345j"));
+    test(S("abcdefghij"), 9, S("1234567890"), 1, 8, S("abcdefghi23456789j"));
+}
+
+void test17()
+{
+    test(S("abcdefghij"), 9, S("1234567890"), 1, 9, S("abcdefghi234567890j"));
+    test(S("abcdefghij"), 9, S("1234567890"), 1, 10, S("abcdefghi234567890j"));
+    test(S("abcdefghij"), 9, S("1234567890"), 5, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 9, S("1234567890"), 5, 1, S("abcdefghi6j"));
+    test(S("abcdefghij"), 9, S("1234567890"), 5, 2, S("abcdefghi67j"));
+    test(S("abcdefghij"), 9, S("1234567890"), 5, 4, S("abcdefghi6789j"));
+    test(S("abcdefghij"), 9, S("1234567890"), 5, 5, S("abcdefghi67890j"));
+    test(S("abcdefghij"), 9, S("1234567890"), 5, 6, S("abcdefghi67890j"));
+    test(S("abcdefghij"), 9, S("1234567890"), 9, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 9, S("1234567890"), 9, 1, S("abcdefghi0j"));
+    test(S("abcdefghij"), 9, S("1234567890"), 9, 2, S("abcdefghi0j"));
+    test(S("abcdefghij"), 9, S("1234567890"), 10, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 9, S("1234567890"), 10, 1, S("abcdefghij"));
+    test(S("abcdefghij"), 9, S("1234567890"), 11, 0, S("can't happen"));
+    test(S("abcdefghij"), 9, S("12345678901234567890"), 0, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 9, S("12345678901234567890"), 0, 1, S("abcdefghi1j"));
+    test(S("abcdefghij"), 9, S("12345678901234567890"), 0, 10, S("abcdefghi1234567890j"));
+    test(S("abcdefghij"), 9, S("12345678901234567890"), 0, 19, S("abcdefghi1234567890123456789j"));
+    test(S("abcdefghij"), 9, S("12345678901234567890"), 0, 20, S("abcdefghi12345678901234567890j"));
+    test(S("abcdefghij"), 9, S("12345678901234567890"), 0, 21, S("abcdefghi12345678901234567890j"));
+    test(S("abcdefghij"), 9, S("12345678901234567890"), 1, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 9, S("12345678901234567890"), 1, 1, S("abcdefghi2j"));
+    test(S("abcdefghij"), 9, S("12345678901234567890"), 1, 9, S("abcdefghi234567890j"));
+    test(S("abcdefghij"), 9, S("12345678901234567890"), 1, 18, S("abcdefghi234567890123456789j"));
+    test(S("abcdefghij"), 9, S("12345678901234567890"), 1, 19, S("abcdefghi2345678901234567890j"));
+    test(S("abcdefghij"), 9, S("12345678901234567890"), 1, 20, S("abcdefghi2345678901234567890j"));
+    test(S("abcdefghij"), 9, S("12345678901234567890"), 10, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 9, S("12345678901234567890"), 10, 1, S("abcdefghi1j"));
+    test(S("abcdefghij"), 9, S("12345678901234567890"), 10, 5, S("abcdefghi12345j"));
+    test(S("abcdefghij"), 9, S("12345678901234567890"), 10, 9, S("abcdefghi123456789j"));
+    test(S("abcdefghij"), 9, S("12345678901234567890"), 10, 10, S("abcdefghi1234567890j"));
+    test(S("abcdefghij"), 9, S("12345678901234567890"), 10, 11, S("abcdefghi1234567890j"));
+    test(S("abcdefghij"), 9, S("12345678901234567890"), 19, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 9, S("12345678901234567890"), 19, 1, S("abcdefghi0j"));
+    test(S("abcdefghij"), 9, S("12345678901234567890"), 19, 2, S("abcdefghi0j"));
+    test(S("abcdefghij"), 9, S("12345678901234567890"), 20, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 9, S("12345678901234567890"), 20, 1, S("abcdefghij"));
+    test(S("abcdefghij"), 9, S("12345678901234567890"), 21, 0, S("can't happen"));
+    test(S("abcdefghij"), 10, S(""), 0, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 10, S(""), 0, 1, S("abcdefghij"));
+    test(S("abcdefghij"), 10, S(""), 1, 0, S("can't happen"));
+    test(S("abcdefghij"), 10, S("12345"), 0, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 10, S("12345"), 0, 1, S("abcdefghij1"));
+    test(S("abcdefghij"), 10, S("12345"), 0, 2, S("abcdefghij12"));
+    test(S("abcdefghij"), 10, S("12345"), 0, 4, S("abcdefghij1234"));
+    test(S("abcdefghij"), 10, S("12345"), 0, 5, S("abcdefghij12345"));
+    test(S("abcdefghij"), 10, S("12345"), 0, 6, S("abcdefghij12345"));
+    test(S("abcdefghij"), 10, S("12345"), 1, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 10, S("12345"), 1, 1, S("abcdefghij2"));
+    test(S("abcdefghij"), 10, S("12345"), 1, 2, S("abcdefghij23"));
+}
+
+void test18()
+{
+    test(S("abcdefghij"), 10, S("12345"), 1, 3, S("abcdefghij234"));
+    test(S("abcdefghij"), 10, S("12345"), 1, 4, S("abcdefghij2345"));
+    test(S("abcdefghij"), 10, S("12345"), 1, 5, S("abcdefghij2345"));
+    test(S("abcdefghij"), 10, S("12345"), 2, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 10, S("12345"), 2, 1, S("abcdefghij3"));
+    test(S("abcdefghij"), 10, S("12345"), 2, 2, S("abcdefghij34"));
+    test(S("abcdefghij"), 10, S("12345"), 2, 3, S("abcdefghij345"));
+    test(S("abcdefghij"), 10, S("12345"), 2, 4, S("abcdefghij345"));
+    test(S("abcdefghij"), 10, S("12345"), 4, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 10, S("12345"), 4, 1, S("abcdefghij5"));
+    test(S("abcdefghij"), 10, S("12345"), 4, 2, S("abcdefghij5"));
+    test(S("abcdefghij"), 10, S("12345"), 5, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 10, S("12345"), 5, 1, S("abcdefghij"));
+    test(S("abcdefghij"), 10, S("12345"), 6, 0, S("can't happen"));
+    test(S("abcdefghij"), 10, S("1234567890"), 0, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 10, S("1234567890"), 0, 1, S("abcdefghij1"));
+    test(S("abcdefghij"), 10, S("1234567890"), 0, 5, S("abcdefghij12345"));
+    test(S("abcdefghij"), 10, S("1234567890"), 0, 9, S("abcdefghij123456789"));
+    test(S("abcdefghij"), 10, S("1234567890"), 0, 10, S("abcdefghij1234567890"));
+    test(S("abcdefghij"), 10, S("1234567890"), 0, 11, S("abcdefghij1234567890"));
+    test(S("abcdefghij"), 10, S("1234567890"), 1, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 10, S("1234567890"), 1, 1, S("abcdefghij2"));
+    test(S("abcdefghij"), 10, S("1234567890"), 1, 4, S("abcdefghij2345"));
+    test(S("abcdefghij"), 10, S("1234567890"), 1, 8, S("abcdefghij23456789"));
+    test(S("abcdefghij"), 10, S("1234567890"), 1, 9, S("abcdefghij234567890"));
+    test(S("abcdefghij"), 10, S("1234567890"), 1, 10, S("abcdefghij234567890"));
+    test(S("abcdefghij"), 10, S("1234567890"), 5, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 10, S("1234567890"), 5, 1, S("abcdefghij6"));
+    test(S("abcdefghij"), 10, S("1234567890"), 5, 2, S("abcdefghij67"));
+    test(S("abcdefghij"), 10, S("1234567890"), 5, 4, S("abcdefghij6789"));
+    test(S("abcdefghij"), 10, S("1234567890"), 5, 5, S("abcdefghij67890"));
+    test(S("abcdefghij"), 10, S("1234567890"), 5, 6, S("abcdefghij67890"));
+    test(S("abcdefghij"), 10, S("1234567890"), 9, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 10, S("1234567890"), 9, 1, S("abcdefghij0"));
+    test(S("abcdefghij"), 10, S("1234567890"), 9, 2, S("abcdefghij0"));
+    test(S("abcdefghij"), 10, S("1234567890"), 10, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 10, S("1234567890"), 10, 1, S("abcdefghij"));
+    test(S("abcdefghij"), 10, S("1234567890"), 11, 0, S("can't happen"));
+    test(S("abcdefghij"), 10, S("12345678901234567890"), 0, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 10, S("12345678901234567890"), 0, 1, S("abcdefghij1"));
+    test(S("abcdefghij"), 10, S("12345678901234567890"), 0, 10, S("abcdefghij1234567890"));
+    test(S("abcdefghij"), 10, S("12345678901234567890"), 0, 19, S("abcdefghij1234567890123456789"));
+    test(S("abcdefghij"), 10, S("12345678901234567890"), 0, 20, S("abcdefghij12345678901234567890"));
+    test(S("abcdefghij"), 10, S("12345678901234567890"), 0, 21, S("abcdefghij12345678901234567890"));
+    test(S("abcdefghij"), 10, S("12345678901234567890"), 1, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 10, S("12345678901234567890"), 1, 1, S("abcdefghij2"));
+    test(S("abcdefghij"), 10, S("12345678901234567890"), 1, 9, S("abcdefghij234567890"));
+    test(S("abcdefghij"), 10, S("12345678901234567890"), 1, 18, S("abcdefghij234567890123456789"));
+    test(S("abcdefghij"), 10, S("12345678901234567890"), 1, 19, S("abcdefghij2345678901234567890"));
+    test(S("abcdefghij"), 10, S("12345678901234567890"), 1, 20, S("abcdefghij2345678901234567890"));
+}
+
+void test19()
+{
+    test(S("abcdefghij"), 10, S("12345678901234567890"), 10, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 10, S("12345678901234567890"), 10, 1, S("abcdefghij1"));
+    test(S("abcdefghij"), 10, S("12345678901234567890"), 10, 5, S("abcdefghij12345"));
+    test(S("abcdefghij"), 10, S("12345678901234567890"), 10, 9, S("abcdefghij123456789"));
+    test(S("abcdefghij"), 10, S("12345678901234567890"), 10, 10, S("abcdefghij1234567890"));
+    test(S("abcdefghij"), 10, S("12345678901234567890"), 10, 11, S("abcdefghij1234567890"));
+    test(S("abcdefghij"), 10, S("12345678901234567890"), 19, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 10, S("12345678901234567890"), 19, 1, S("abcdefghij0"));
+    test(S("abcdefghij"), 10, S("12345678901234567890"), 19, 2, S("abcdefghij0"));
+    test(S("abcdefghij"), 10, S("12345678901234567890"), 20, 0, S("abcdefghij"));
+    test(S("abcdefghij"), 10, S("12345678901234567890"), 20, 1, S("abcdefghij"));
+    test(S("abcdefghij"), 10, S("12345678901234567890"), 21, 0, S("can't happen"));
+    test(S("abcdefghij"), 11, S(""), 0, 0, S("can't happen"));
+    test(S("abcdefghij"), 11, S(""), 0, 1, S("can't happen"));
+    test(S("abcdefghij"), 11, S(""), 1, 0, S("can't happen"));
+    test(S("abcdefghij"), 11, S("12345"), 0, 0, S("can't happen"));
+    test(S("abcdefghij"), 11, S("12345"), 0, 1, S("can't happen"));
+    test(S("abcdefghij"), 11, S("12345"), 0, 2, S("can't happen"));
+    test(S("abcdefghij"), 11, S("12345"), 0, 4, S("can't happen"));
+    test(S("abcdefghij"), 11, S("12345"), 0, 5, S("can't happen"));
+    test(S("abcdefghij"), 11, S("12345"), 0, 6, S("can't happen"));
+    test(S("abcdefghij"), 11, S("12345"), 1, 0, S("can't happen"));
+    test(S("abcdefghij"), 11, S("12345"), 1, 1, S("can't happen"));
+    test(S("abcdefghij"), 11, S("12345"), 1, 2, S("can't happen"));
+    test(S("abcdefghij"), 11, S("12345"), 1, 3, S("can't happen"));
+    test(S("abcdefghij"), 11, S("12345"), 1, 4, S("can't happen"));
+    test(S("abcdefghij"), 11, S("12345"), 1, 5, S("can't happen"));
+    test(S("abcdefghij"), 11, S("12345"), 2, 0, S("can't happen"));
+    test(S("abcdefghij"), 11, S("12345"), 2, 1, S("can't happen"));
+    test(S("abcdefghij"), 11, S("12345"), 2, 2, S("can't happen"));
+    test(S("abcdefghij"), 11, S("12345"), 2, 3, S("can't happen"));
+    test(S("abcdefghij"), 11, S("12345"), 2, 4, S("can't happen"));
+    test(S("abcdefghij"), 11, S("12345"), 4, 0, S("can't happen"));
+    test(S("abcdefghij"), 11, S("12345"), 4, 1, S("can't happen"));
+    test(S("abcdefghij"), 11, S("12345"), 4, 2, S("can't happen"));
+    test(S("abcdefghij"), 11, S("12345"), 5, 0, S("can't happen"));
+    test(S("abcdefghij"), 11, S("12345"), 5, 1, S("can't happen"));
+    test(S("abcdefghij"), 11, S("12345"), 6, 0, S("can't happen"));
+    test(S("abcdefghij"), 11, S("1234567890"), 0, 0, S("can't happen"));
+    test(S("abcdefghij"), 11, S("1234567890"), 0, 1, S("can't happen"));
+    test(S("abcdefghij"), 11, S("1234567890"), 0, 5, S("can't happen"));
+    test(S("abcdefghij"), 11, S("1234567890"), 0, 9, S("can't happen"));
+    test(S("abcdefghij"), 11, S("1234567890"), 0, 10, S("can't happen"));
+    test(S("abcdefghij"), 11, S("1234567890"), 0, 11, S("can't happen"));
+    test(S("abcdefghij"), 11, S("1234567890"), 1, 0, S("can't happen"));
+    test(S("abcdefghij"), 11, S("1234567890"), 1, 1, S("can't happen"));
+    test(S("abcdefghij"), 11, S("1234567890"), 1, 4, S("can't happen"));
+    test(S("abcdefghij"), 11, S("1234567890"), 1, 8, S("can't happen"));
+    test(S("abcdefghij"), 11, S("1234567890"), 1, 9, S("can't happen"));
+    test(S("abcdefghij"), 11, S("1234567890"), 1, 10, S("can't happen"));
+}
+
+void test20()
+{
+    test(S("abcdefghij"), 11, S("1234567890"), 5, 0, S("can't happen"));
+    test(S("abcdefghij"), 11, S("1234567890"), 5, 1, S("can't happen"));
+    test(S("abcdefghij"), 11, S("1234567890"), 5, 2, S("can't happen"));
+    test(S("abcdefghij"), 11, S("1234567890"), 5, 4, S("can't happen"));
+    test(S("abcdefghij"), 11, S("1234567890"), 5, 5, S("can't happen"));
+    test(S("abcdefghij"), 11, S("1234567890"), 5, 6, S("can't happen"));
+    test(S("abcdefghij"), 11, S("1234567890"), 9, 0, S("can't happen"));
+    test(S("abcdefghij"), 11, S("1234567890"), 9, 1, S("can't happen"));
+    test(S("abcdefghij"), 11, S("1234567890"), 9, 2, S("can't happen"));
+    test(S("abcdefghij"), 11, S("1234567890"), 10, 0, S("can't happen"));
+    test(S("abcdefghij"), 11, S("1234567890"), 10, 1, S("can't happen"));
+    test(S("abcdefghij"), 11, S("1234567890"), 11, 0, S("can't happen"));
+    test(S("abcdefghij"), 11, S("12345678901234567890"), 0, 0, S("can't happen"));
+    test(S("abcdefghij"), 11, S("12345678901234567890"), 0, 1, S("can't happen"));
+    test(S("abcdefghij"), 11, S("12345678901234567890"), 0, 10, S("can't happen"));
+    test(S("abcdefghij"), 11, S("12345678901234567890"), 0, 19, S("can't happen"));
+    test(S("abcdefghij"), 11, S("12345678901234567890"), 0, 20, S("can't happen"));
+    test(S("abcdefghij"), 11, S("12345678901234567890"), 0, 21, S("can't happen"));
+    test(S("abcdefghij"), 11, S("12345678901234567890"), 1, 0, S("can't happen"));
+    test(S("abcdefghij"), 11, S("12345678901234567890"), 1, 1, S("can't happen"));
+    test(S("abcdefghij"), 11, S("12345678901234567890"), 1, 9, S("can't happen"));
+    test(S("abcdefghij"), 11, S("12345678901234567890"), 1, 18, S("can't happen"));
+    test(S("abcdefghij"), 11, S("12345678901234567890"), 1, 19, S("can't happen"));
+    test(S("abcdefghij"), 11, S("12345678901234567890"), 1, 20, S("can't happen"));
+    test(S("abcdefghij"), 11, S("12345678901234567890"), 10, 0, S("can't happen"));
+    test(S("abcdefghij"), 11, S("12345678901234567890"), 10, 1, S("can't happen"));
+    test(S("abcdefghij"), 11, S("12345678901234567890"), 10, 5, S("can't happen"));
+    test(S("abcdefghij"), 11, S("12345678901234567890"), 10, 9, S("can't happen"));
+    test(S("abcdefghij"), 11, S("12345678901234567890"), 10, 10, S("can't happen"));
+    test(S("abcdefghij"), 11, S("12345678901234567890"), 10, 11, S("can't happen"));
+    test(S("abcdefghij"), 11, S("12345678901234567890"), 19, 0, S("can't happen"));
+    test(S("abcdefghij"), 11, S("12345678901234567890"), 19, 1, S("can't happen"));
+    test(S("abcdefghij"), 11, S("12345678901234567890"), 19, 2, S("can't happen"));
+    test(S("abcdefghij"), 11, S("12345678901234567890"), 20, 0, S("can't happen"));
+    test(S("abcdefghij"), 11, S("12345678901234567890"), 20, 1, S("can't happen"));
+    test(S("abcdefghij"), 11, S("12345678901234567890"), 21, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 0, S(""), 0, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, S(""), 0, 1, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, S(""), 1, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 0, S("12345"), 0, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, S("12345"), 0, 1, S("1abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, S("12345"), 0, 2, S("12abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, S("12345"), 0, 4, S("1234abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, S("12345"), 0, 5, S("12345abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, S("12345"), 0, 6, S("12345abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, S("12345"), 1, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, S("12345"), 1, 1, S("2abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, S("12345"), 1, 2, S("23abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, S("12345"), 1, 3, S("234abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, S("12345"), 1, 4, S("2345abcdefghijklmnopqrst"));
+}
+
+void test21()
+{
+    test(S("abcdefghijklmnopqrst"), 0, S("12345"), 1, 5, S("2345abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, S("12345"), 2, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, S("12345"), 2, 1, S("3abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, S("12345"), 2, 2, S("34abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, S("12345"), 2, 3, S("345abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, S("12345"), 2, 4, S("345abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, S("12345"), 4, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, S("12345"), 4, 1, S("5abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, S("12345"), 4, 2, S("5abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, S("12345"), 5, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, S("12345"), 5, 1, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, S("12345"), 6, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 0, S("1234567890"), 0, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, S("1234567890"), 0, 1, S("1abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, S("1234567890"), 0, 5, S("12345abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, S("1234567890"), 0, 9, S("123456789abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, S("1234567890"), 0, 10, S("1234567890abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, S("1234567890"), 0, 11, S("1234567890abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, S("1234567890"), 1, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, S("1234567890"), 1, 1, S("2abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, S("1234567890"), 1, 4, S("2345abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, S("1234567890"), 1, 8, S("23456789abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, S("1234567890"), 1, 9, S("234567890abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, S("1234567890"), 1, 10, S("234567890abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, S("1234567890"), 5, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, S("1234567890"), 5, 1, S("6abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, S("1234567890"), 5, 2, S("67abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, S("1234567890"), 5, 4, S("6789abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, S("1234567890"), 5, 5, S("67890abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, S("1234567890"), 5, 6, S("67890abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, S("1234567890"), 9, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, S("1234567890"), 9, 1, S("0abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, S("1234567890"), 9, 2, S("0abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, S("1234567890"), 10, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, S("1234567890"), 10, 1, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, S("1234567890"), 11, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 0, S("12345678901234567890"), 0, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, S("12345678901234567890"), 0, 1, S("1abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, S("12345678901234567890"), 0, 10, S("1234567890abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, S("12345678901234567890"), 0, 19, S("1234567890123456789abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, S("12345678901234567890"), 0, 20, S("12345678901234567890abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, S("12345678901234567890"), 0, 21, S("12345678901234567890abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, S("12345678901234567890"), 1, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, S("12345678901234567890"), 1, 1, S("2abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, S("12345678901234567890"), 1, 9, S("234567890abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, S("12345678901234567890"), 1, 18, S("234567890123456789abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, S("12345678901234567890"), 1, 19, S("2345678901234567890abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, S("12345678901234567890"), 1, 20, S("2345678901234567890abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, S("12345678901234567890"), 10, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, S("12345678901234567890"), 10, 1, S("1abcdefghijklmnopqrst"));
+}
+
+void test22()
+{
+    test(S("abcdefghijklmnopqrst"), 0, S("12345678901234567890"), 10, 5, S("12345abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, S("12345678901234567890"), 10, 9, S("123456789abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, S("12345678901234567890"), 10, 10, S("1234567890abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, S("12345678901234567890"), 10, 11, S("1234567890abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, S("12345678901234567890"), 19, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, S("12345678901234567890"), 19, 1, S("0abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, S("12345678901234567890"), 19, 2, S("0abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, S("12345678901234567890"), 20, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, S("12345678901234567890"), 20, 1, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 0, S("12345678901234567890"), 21, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 1, S(""), 0, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, S(""), 0, 1, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, S(""), 1, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 1, S("12345"), 0, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, S("12345"), 0, 1, S("a1bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, S("12345"), 0, 2, S("a12bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, S("12345"), 0, 4, S("a1234bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, S("12345"), 0, 5, S("a12345bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, S("12345"), 0, 6, S("a12345bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, S("12345"), 1, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, S("12345"), 1, 1, S("a2bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, S("12345"), 1, 2, S("a23bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, S("12345"), 1, 3, S("a234bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, S("12345"), 1, 4, S("a2345bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, S("12345"), 1, 5, S("a2345bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, S("12345"), 2, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, S("12345"), 2, 1, S("a3bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, S("12345"), 2, 2, S("a34bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, S("12345"), 2, 3, S("a345bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, S("12345"), 2, 4, S("a345bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, S("12345"), 4, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, S("12345"), 4, 1, S("a5bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, S("12345"), 4, 2, S("a5bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, S("12345"), 5, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, S("12345"), 5, 1, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, S("12345"), 6, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 1, S("1234567890"), 0, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, S("1234567890"), 0, 1, S("a1bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, S("1234567890"), 0, 5, S("a12345bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, S("1234567890"), 0, 9, S("a123456789bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, S("1234567890"), 0, 10, S("a1234567890bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, S("1234567890"), 0, 11, S("a1234567890bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, S("1234567890"), 1, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, S("1234567890"), 1, 1, S("a2bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, S("1234567890"), 1, 4, S("a2345bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, S("1234567890"), 1, 8, S("a23456789bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, S("1234567890"), 1, 9, S("a234567890bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, S("1234567890"), 1, 10, S("a234567890bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, S("1234567890"), 5, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, S("1234567890"), 5, 1, S("a6bcdefghijklmnopqrst"));
+}
+
+void test23()
+{
+    test(S("abcdefghijklmnopqrst"), 1, S("1234567890"), 5, 2, S("a67bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, S("1234567890"), 5, 4, S("a6789bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, S("1234567890"), 5, 5, S("a67890bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, S("1234567890"), 5, 6, S("a67890bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, S("1234567890"), 9, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, S("1234567890"), 9, 1, S("a0bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, S("1234567890"), 9, 2, S("a0bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, S("1234567890"), 10, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, S("1234567890"), 10, 1, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, S("1234567890"), 11, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 1, S("12345678901234567890"), 0, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, S("12345678901234567890"), 0, 1, S("a1bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, S("12345678901234567890"), 0, 10, S("a1234567890bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, S("12345678901234567890"), 0, 19, S("a1234567890123456789bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, S("12345678901234567890"), 0, 20, S("a12345678901234567890bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, S("12345678901234567890"), 0, 21, S("a12345678901234567890bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, S("12345678901234567890"), 1, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, S("12345678901234567890"), 1, 1, S("a2bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, S("12345678901234567890"), 1, 9, S("a234567890bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, S("12345678901234567890"), 1, 18, S("a234567890123456789bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, S("12345678901234567890"), 1, 19, S("a2345678901234567890bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, S("12345678901234567890"), 1, 20, S("a2345678901234567890bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, S("12345678901234567890"), 10, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, S("12345678901234567890"), 10, 1, S("a1bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, S("12345678901234567890"), 10, 5, S("a12345bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, S("12345678901234567890"), 10, 9, S("a123456789bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, S("12345678901234567890"), 10, 10, S("a1234567890bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, S("12345678901234567890"), 10, 11, S("a1234567890bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, S("12345678901234567890"), 19, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, S("12345678901234567890"), 19, 1, S("a0bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, S("12345678901234567890"), 19, 2, S("a0bcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, S("12345678901234567890"), 20, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, S("12345678901234567890"), 20, 1, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 1, S("12345678901234567890"), 21, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 10, S(""), 0, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, S(""), 0, 1, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, S(""), 1, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 10, S("12345"), 0, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, S("12345"), 0, 1, S("abcdefghij1klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, S("12345"), 0, 2, S("abcdefghij12klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, S("12345"), 0, 4, S("abcdefghij1234klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, S("12345"), 0, 5, S("abcdefghij12345klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, S("12345"), 0, 6, S("abcdefghij12345klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, S("12345"), 1, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, S("12345"), 1, 1, S("abcdefghij2klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, S("12345"), 1, 2, S("abcdefghij23klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, S("12345"), 1, 3, S("abcdefghij234klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, S("12345"), 1, 4, S("abcdefghij2345klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, S("12345"), 1, 5, S("abcdefghij2345klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, S("12345"), 2, 0, S("abcdefghijklmnopqrst"));
+}
+
+void test24()
+{
+    test(S("abcdefghijklmnopqrst"), 10, S("12345"), 2, 1, S("abcdefghij3klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, S("12345"), 2, 2, S("abcdefghij34klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, S("12345"), 2, 3, S("abcdefghij345klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, S("12345"), 2, 4, S("abcdefghij345klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, S("12345"), 4, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, S("12345"), 4, 1, S("abcdefghij5klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, S("12345"), 4, 2, S("abcdefghij5klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, S("12345"), 5, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, S("12345"), 5, 1, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, S("12345"), 6, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 10, S("1234567890"), 0, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, S("1234567890"), 0, 1, S("abcdefghij1klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, S("1234567890"), 0, 5, S("abcdefghij12345klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, S("1234567890"), 0, 9, S("abcdefghij123456789klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, S("1234567890"), 0, 10, S("abcdefghij1234567890klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, S("1234567890"), 0, 11, S("abcdefghij1234567890klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, S("1234567890"), 1, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, S("1234567890"), 1, 1, S("abcdefghij2klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, S("1234567890"), 1, 4, S("abcdefghij2345klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, S("1234567890"), 1, 8, S("abcdefghij23456789klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, S("1234567890"), 1, 9, S("abcdefghij234567890klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, S("1234567890"), 1, 10, S("abcdefghij234567890klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, S("1234567890"), 5, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, S("1234567890"), 5, 1, S("abcdefghij6klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, S("1234567890"), 5, 2, S("abcdefghij67klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, S("1234567890"), 5, 4, S("abcdefghij6789klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, S("1234567890"), 5, 5, S("abcdefghij67890klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, S("1234567890"), 5, 6, S("abcdefghij67890klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, S("1234567890"), 9, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, S("1234567890"), 9, 1, S("abcdefghij0klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, S("1234567890"), 9, 2, S("abcdefghij0klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, S("1234567890"), 10, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, S("1234567890"), 10, 1, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, S("1234567890"), 11, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 10, S("12345678901234567890"), 0, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, S("12345678901234567890"), 0, 1, S("abcdefghij1klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, S("12345678901234567890"), 0, 10, S("abcdefghij1234567890klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, S("12345678901234567890"), 0, 19, S("abcdefghij1234567890123456789klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, S("12345678901234567890"), 0, 20, S("abcdefghij12345678901234567890klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, S("12345678901234567890"), 0, 21, S("abcdefghij12345678901234567890klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, S("12345678901234567890"), 1, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, S("12345678901234567890"), 1, 1, S("abcdefghij2klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, S("12345678901234567890"), 1, 9, S("abcdefghij234567890klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, S("12345678901234567890"), 1, 18, S("abcdefghij234567890123456789klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, S("12345678901234567890"), 1, 19, S("abcdefghij2345678901234567890klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, S("12345678901234567890"), 1, 20, S("abcdefghij2345678901234567890klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, S("12345678901234567890"), 10, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, S("12345678901234567890"), 10, 1, S("abcdefghij1klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, S("12345678901234567890"), 10, 5, S("abcdefghij12345klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, S("12345678901234567890"), 10, 9, S("abcdefghij123456789klmnopqrst"));
+}
+
+void test25()
+{
+    test(S("abcdefghijklmnopqrst"), 10, S("12345678901234567890"), 10, 10, S("abcdefghij1234567890klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, S("12345678901234567890"), 10, 11, S("abcdefghij1234567890klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, S("12345678901234567890"), 19, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, S("12345678901234567890"), 19, 1, S("abcdefghij0klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, S("12345678901234567890"), 19, 2, S("abcdefghij0klmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, S("12345678901234567890"), 20, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, S("12345678901234567890"), 20, 1, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 10, S("12345678901234567890"), 21, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 19, S(""), 0, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 19, S(""), 0, 1, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 19, S(""), 1, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 19, S("12345"), 0, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 19, S("12345"), 0, 1, S("abcdefghijklmnopqrs1t"));
+    test(S("abcdefghijklmnopqrst"), 19, S("12345"), 0, 2, S("abcdefghijklmnopqrs12t"));
+    test(S("abcdefghijklmnopqrst"), 19, S("12345"), 0, 4, S("abcdefghijklmnopqrs1234t"));
+    test(S("abcdefghijklmnopqrst"), 19, S("12345"), 0, 5, S("abcdefghijklmnopqrs12345t"));
+    test(S("abcdefghijklmnopqrst"), 19, S("12345"), 0, 6, S("abcdefghijklmnopqrs12345t"));
+    test(S("abcdefghijklmnopqrst"), 19, S("12345"), 1, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 19, S("12345"), 1, 1, S("abcdefghijklmnopqrs2t"));
+    test(S("abcdefghijklmnopqrst"), 19, S("12345"), 1, 2, S("abcdefghijklmnopqrs23t"));
+    test(S("abcdefghijklmnopqrst"), 19, S("12345"), 1, 3, S("abcdefghijklmnopqrs234t"));
+    test(S("abcdefghijklmnopqrst"), 19, S("12345"), 1, 4, S("abcdefghijklmnopqrs2345t"));
+    test(S("abcdefghijklmnopqrst"), 19, S("12345"), 1, 5, S("abcdefghijklmnopqrs2345t"));
+    test(S("abcdefghijklmnopqrst"), 19, S("12345"), 2, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 19, S("12345"), 2, 1, S("abcdefghijklmnopqrs3t"));
+    test(S("abcdefghijklmnopqrst"), 19, S("12345"), 2, 2, S("abcdefghijklmnopqrs34t"));
+    test(S("abcdefghijklmnopqrst"), 19, S("12345"), 2, 3, S("abcdefghijklmnopqrs345t"));
+    test(S("abcdefghijklmnopqrst"), 19, S("12345"), 2, 4, S("abcdefghijklmnopqrs345t"));
+    test(S("abcdefghijklmnopqrst"), 19, S("12345"), 4, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 19, S("12345"), 4, 1, S("abcdefghijklmnopqrs5t"));
+    test(S("abcdefghijklmnopqrst"), 19, S("12345"), 4, 2, S("abcdefghijklmnopqrs5t"));
+    test(S("abcdefghijklmnopqrst"), 19, S("12345"), 5, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 19, S("12345"), 5, 1, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 19, S("12345"), 6, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 19, S("1234567890"), 0, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 19, S("1234567890"), 0, 1, S("abcdefghijklmnopqrs1t"));
+    test(S("abcdefghijklmnopqrst"), 19, S("1234567890"), 0, 5, S("abcdefghijklmnopqrs12345t"));
+    test(S("abcdefghijklmnopqrst"), 19, S("1234567890"), 0, 9, S("abcdefghijklmnopqrs123456789t"));
+    test(S("abcdefghijklmnopqrst"), 19, S("1234567890"), 0, 10, S("abcdefghijklmnopqrs1234567890t"));
+    test(S("abcdefghijklmnopqrst"), 19, S("1234567890"), 0, 11, S("abcdefghijklmnopqrs1234567890t"));
+    test(S("abcdefghijklmnopqrst"), 19, S("1234567890"), 1, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 19, S("1234567890"), 1, 1, S("abcdefghijklmnopqrs2t"));
+    test(S("abcdefghijklmnopqrst"), 19, S("1234567890"), 1, 4, S("abcdefghijklmnopqrs2345t"));
+    test(S("abcdefghijklmnopqrst"), 19, S("1234567890"), 1, 8, S("abcdefghijklmnopqrs23456789t"));
+    test(S("abcdefghijklmnopqrst"), 19, S("1234567890"), 1, 9, S("abcdefghijklmnopqrs234567890t"));
+    test(S("abcdefghijklmnopqrst"), 19, S("1234567890"), 1, 10, S("abcdefghijklmnopqrs234567890t"));
+    test(S("abcdefghijklmnopqrst"), 19, S("1234567890"), 5, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 19, S("1234567890"), 5, 1, S("abcdefghijklmnopqrs6t"));
+    test(S("abcdefghijklmnopqrst"), 19, S("1234567890"), 5, 2, S("abcdefghijklmnopqrs67t"));
+    test(S("abcdefghijklmnopqrst"), 19, S("1234567890"), 5, 4, S("abcdefghijklmnopqrs6789t"));
+}
+
+void test26()
+{
+    test(S("abcdefghijklmnopqrst"), 19, S("1234567890"), 5, 5, S("abcdefghijklmnopqrs67890t"));
+    test(S("abcdefghijklmnopqrst"), 19, S("1234567890"), 5, 6, S("abcdefghijklmnopqrs67890t"));
+    test(S("abcdefghijklmnopqrst"), 19, S("1234567890"), 9, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 19, S("1234567890"), 9, 1, S("abcdefghijklmnopqrs0t"));
+    test(S("abcdefghijklmnopqrst"), 19, S("1234567890"), 9, 2, S("abcdefghijklmnopqrs0t"));
+    test(S("abcdefghijklmnopqrst"), 19, S("1234567890"), 10, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 19, S("1234567890"), 10, 1, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 19, S("1234567890"), 11, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 19, S("12345678901234567890"), 0, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 19, S("12345678901234567890"), 0, 1, S("abcdefghijklmnopqrs1t"));
+    test(S("abcdefghijklmnopqrst"), 19, S("12345678901234567890"), 0, 10, S("abcdefghijklmnopqrs1234567890t"));
+    test(S("abcdefghijklmnopqrst"), 19, S("12345678901234567890"), 0, 19, S("abcdefghijklmnopqrs1234567890123456789t"));
+    test(S("abcdefghijklmnopqrst"), 19, S("12345678901234567890"), 0, 20, S("abcdefghijklmnopqrs12345678901234567890t"));
+    test(S("abcdefghijklmnopqrst"), 19, S("12345678901234567890"), 0, 21, S("abcdefghijklmnopqrs12345678901234567890t"));
+    test(S("abcdefghijklmnopqrst"), 19, S("12345678901234567890"), 1, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 19, S("12345678901234567890"), 1, 1, S("abcdefghijklmnopqrs2t"));
+    test(S("abcdefghijklmnopqrst"), 19, S("12345678901234567890"), 1, 9, S("abcdefghijklmnopqrs234567890t"));
+    test(S("abcdefghijklmnopqrst"), 19, S("12345678901234567890"), 1, 18, S("abcdefghijklmnopqrs234567890123456789t"));
+    test(S("abcdefghijklmnopqrst"), 19, S("12345678901234567890"), 1, 19, S("abcdefghijklmnopqrs2345678901234567890t"));
+    test(S("abcdefghijklmnopqrst"), 19, S("12345678901234567890"), 1, 20, S("abcdefghijklmnopqrs2345678901234567890t"));
+    test(S("abcdefghijklmnopqrst"), 19, S("12345678901234567890"), 10, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 19, S("12345678901234567890"), 10, 1, S("abcdefghijklmnopqrs1t"));
+    test(S("abcdefghijklmnopqrst"), 19, S("12345678901234567890"), 10, 5, S("abcdefghijklmnopqrs12345t"));
+    test(S("abcdefghijklmnopqrst"), 19, S("12345678901234567890"), 10, 9, S("abcdefghijklmnopqrs123456789t"));
+    test(S("abcdefghijklmnopqrst"), 19, S("12345678901234567890"), 10, 10, S("abcdefghijklmnopqrs1234567890t"));
+    test(S("abcdefghijklmnopqrst"), 19, S("12345678901234567890"), 10, 11, S("abcdefghijklmnopqrs1234567890t"));
+    test(S("abcdefghijklmnopqrst"), 19, S("12345678901234567890"), 19, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 19, S("12345678901234567890"), 19, 1, S("abcdefghijklmnopqrs0t"));
+    test(S("abcdefghijklmnopqrst"), 19, S("12345678901234567890"), 19, 2, S("abcdefghijklmnopqrs0t"));
+    test(S("abcdefghijklmnopqrst"), 19, S("12345678901234567890"), 20, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 19, S("12345678901234567890"), 20, 1, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 19, S("12345678901234567890"), 21, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 20, S(""), 0, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 20, S(""), 0, 1, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 20, S(""), 1, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 20, S("12345"), 0, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 20, S("12345"), 0, 1, S("abcdefghijklmnopqrst1"));
+    test(S("abcdefghijklmnopqrst"), 20, S("12345"), 0, 2, S("abcdefghijklmnopqrst12"));
+    test(S("abcdefghijklmnopqrst"), 20, S("12345"), 0, 4, S("abcdefghijklmnopqrst1234"));
+    test(S("abcdefghijklmnopqrst"), 20, S("12345"), 0, 5, S("abcdefghijklmnopqrst12345"));
+    test(S("abcdefghijklmnopqrst"), 20, S("12345"), 0, 6, S("abcdefghijklmnopqrst12345"));
+    test(S("abcdefghijklmnopqrst"), 20, S("12345"), 1, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 20, S("12345"), 1, 1, S("abcdefghijklmnopqrst2"));
+    test(S("abcdefghijklmnopqrst"), 20, S("12345"), 1, 2, S("abcdefghijklmnopqrst23"));
+    test(S("abcdefghijklmnopqrst"), 20, S("12345"), 1, 3, S("abcdefghijklmnopqrst234"));
+    test(S("abcdefghijklmnopqrst"), 20, S("12345"), 1, 4, S("abcdefghijklmnopqrst2345"));
+    test(S("abcdefghijklmnopqrst"), 20, S("12345"), 1, 5, S("abcdefghijklmnopqrst2345"));
+    test(S("abcdefghijklmnopqrst"), 20, S("12345"), 2, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 20, S("12345"), 2, 1, S("abcdefghijklmnopqrst3"));
+    test(S("abcdefghijklmnopqrst"), 20, S("12345"), 2, 2, S("abcdefghijklmnopqrst34"));
+}
+
+void test27()
+{
+    test(S("abcdefghijklmnopqrst"), 20, S("12345"), 2, 3, S("abcdefghijklmnopqrst345"));
+    test(S("abcdefghijklmnopqrst"), 20, S("12345"), 2, 4, S("abcdefghijklmnopqrst345"));
+    test(S("abcdefghijklmnopqrst"), 20, S("12345"), 4, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 20, S("12345"), 4, 1, S("abcdefghijklmnopqrst5"));
+    test(S("abcdefghijklmnopqrst"), 20, S("12345"), 4, 2, S("abcdefghijklmnopqrst5"));
+    test(S("abcdefghijklmnopqrst"), 20, S("12345"), 5, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 20, S("12345"), 5, 1, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 20, S("12345"), 6, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 20, S("1234567890"), 0, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 20, S("1234567890"), 0, 1, S("abcdefghijklmnopqrst1"));
+    test(S("abcdefghijklmnopqrst"), 20, S("1234567890"), 0, 5, S("abcdefghijklmnopqrst12345"));
+    test(S("abcdefghijklmnopqrst"), 20, S("1234567890"), 0, 9, S("abcdefghijklmnopqrst123456789"));
+    test(S("abcdefghijklmnopqrst"), 20, S("1234567890"), 0, 10, S("abcdefghijklmnopqrst1234567890"));
+    test(S("abcdefghijklmnopqrst"), 20, S("1234567890"), 0, 11, S("abcdefghijklmnopqrst1234567890"));
+    test(S("abcdefghijklmnopqrst"), 20, S("1234567890"), 1, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 20, S("1234567890"), 1, 1, S("abcdefghijklmnopqrst2"));
+    test(S("abcdefghijklmnopqrst"), 20, S("1234567890"), 1, 4, S("abcdefghijklmnopqrst2345"));
+    test(S("abcdefghijklmnopqrst"), 20, S("1234567890"), 1, 8, S("abcdefghijklmnopqrst23456789"));
+    test(S("abcdefghijklmnopqrst"), 20, S("1234567890"), 1, 9, S("abcdefghijklmnopqrst234567890"));
+    test(S("abcdefghijklmnopqrst"), 20, S("1234567890"), 1, 10, S("abcdefghijklmnopqrst234567890"));
+    test(S("abcdefghijklmnopqrst"), 20, S("1234567890"), 5, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 20, S("1234567890"), 5, 1, S("abcdefghijklmnopqrst6"));
+    test(S("abcdefghijklmnopqrst"), 20, S("1234567890"), 5, 2, S("abcdefghijklmnopqrst67"));
+    test(S("abcdefghijklmnopqrst"), 20, S("1234567890"), 5, 4, S("abcdefghijklmnopqrst6789"));
+    test(S("abcdefghijklmnopqrst"), 20, S("1234567890"), 5, 5, S("abcdefghijklmnopqrst67890"));
+    test(S("abcdefghijklmnopqrst"), 20, S("1234567890"), 5, 6, S("abcdefghijklmnopqrst67890"));
+    test(S("abcdefghijklmnopqrst"), 20, S("1234567890"), 9, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 20, S("1234567890"), 9, 1, S("abcdefghijklmnopqrst0"));
+    test(S("abcdefghijklmnopqrst"), 20, S("1234567890"), 9, 2, S("abcdefghijklmnopqrst0"));
+    test(S("abcdefghijklmnopqrst"), 20, S("1234567890"), 10, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 20, S("1234567890"), 10, 1, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 20, S("1234567890"), 11, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 20, S("12345678901234567890"), 0, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 20, S("12345678901234567890"), 0, 1, S("abcdefghijklmnopqrst1"));
+    test(S("abcdefghijklmnopqrst"), 20, S("12345678901234567890"), 0, 10, S("abcdefghijklmnopqrst1234567890"));
+    test(S("abcdefghijklmnopqrst"), 20, S("12345678901234567890"), 0, 19, S("abcdefghijklmnopqrst1234567890123456789"));
+    test(S("abcdefghijklmnopqrst"), 20, S("12345678901234567890"), 0, 20, S("abcdefghijklmnopqrst12345678901234567890"));
+    test(S("abcdefghijklmnopqrst"), 20, S("12345678901234567890"), 0, 21, S("abcdefghijklmnopqrst12345678901234567890"));
+    test(S("abcdefghijklmnopqrst"), 20, S("12345678901234567890"), 1, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 20, S("12345678901234567890"), 1, 1, S("abcdefghijklmnopqrst2"));
+    test(S("abcdefghijklmnopqrst"), 20, S("12345678901234567890"), 1, 9, S("abcdefghijklmnopqrst234567890"));
+    test(S("abcdefghijklmnopqrst"), 20, S("12345678901234567890"), 1, 18, S("abcdefghijklmnopqrst234567890123456789"));
+    test(S("abcdefghijklmnopqrst"), 20, S("12345678901234567890"), 1, 19, S("abcdefghijklmnopqrst2345678901234567890"));
+    test(S("abcdefghijklmnopqrst"), 20, S("12345678901234567890"), 1, 20, S("abcdefghijklmnopqrst2345678901234567890"));
+    test(S("abcdefghijklmnopqrst"), 20, S("12345678901234567890"), 10, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 20, S("12345678901234567890"), 10, 1, S("abcdefghijklmnopqrst1"));
+    test(S("abcdefghijklmnopqrst"), 20, S("12345678901234567890"), 10, 5, S("abcdefghijklmnopqrst12345"));
+    test(S("abcdefghijklmnopqrst"), 20, S("12345678901234567890"), 10, 9, S("abcdefghijklmnopqrst123456789"));
+    test(S("abcdefghijklmnopqrst"), 20, S("12345678901234567890"), 10, 10, S("abcdefghijklmnopqrst1234567890"));
+    test(S("abcdefghijklmnopqrst"), 20, S("12345678901234567890"), 10, 11, S("abcdefghijklmnopqrst1234567890"));
+}
+
+void test28()
+{
+    test(S("abcdefghijklmnopqrst"), 20, S("12345678901234567890"), 19, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 20, S("12345678901234567890"), 19, 1, S("abcdefghijklmnopqrst0"));
+    test(S("abcdefghijklmnopqrst"), 20, S("12345678901234567890"), 19, 2, S("abcdefghijklmnopqrst0"));
+    test(S("abcdefghijklmnopqrst"), 20, S("12345678901234567890"), 20, 0, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 20, S("12345678901234567890"), 20, 1, S("abcdefghijklmnopqrst"));
+    test(S("abcdefghijklmnopqrst"), 20, S("12345678901234567890"), 21, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, S(""), 0, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, S(""), 0, 1, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, S(""), 1, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, S("12345"), 0, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, S("12345"), 0, 1, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, S("12345"), 0, 2, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, S("12345"), 0, 4, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, S("12345"), 0, 5, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, S("12345"), 0, 6, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, S("12345"), 1, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, S("12345"), 1, 1, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, S("12345"), 1, 2, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, S("12345"), 1, 3, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, S("12345"), 1, 4, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, S("12345"), 1, 5, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, S("12345"), 2, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, S("12345"), 2, 1, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, S("12345"), 2, 2, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, S("12345"), 2, 3, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, S("12345"), 2, 4, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, S("12345"), 4, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, S("12345"), 4, 1, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, S("12345"), 4, 2, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, S("12345"), 5, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, S("12345"), 5, 1, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, S("12345"), 6, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, S("1234567890"), 0, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, S("1234567890"), 0, 1, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, S("1234567890"), 0, 5, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, S("1234567890"), 0, 9, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, S("1234567890"), 0, 10, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, S("1234567890"), 0, 11, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, S("1234567890"), 1, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, S("1234567890"), 1, 1, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, S("1234567890"), 1, 4, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, S("1234567890"), 1, 8, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, S("1234567890"), 1, 9, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, S("1234567890"), 1, 10, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, S("1234567890"), 5, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, S("1234567890"), 5, 1, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, S("1234567890"), 5, 2, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, S("1234567890"), 5, 4, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, S("1234567890"), 5, 5, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, S("1234567890"), 5, 6, S("can't happen"));
+}
+
+void test29()
+{
+    test(S("abcdefghijklmnopqrst"), 21, S("1234567890"), 9, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, S("1234567890"), 9, 1, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, S("1234567890"), 9, 2, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, S("1234567890"), 10, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, S("1234567890"), 10, 1, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, S("1234567890"), 11, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, S("12345678901234567890"), 0, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, S("12345678901234567890"), 0, 1, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, S("12345678901234567890"), 0, 10, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, S("12345678901234567890"), 0, 19, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, S("12345678901234567890"), 0, 20, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, S("12345678901234567890"), 0, 21, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, S("12345678901234567890"), 1, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, S("12345678901234567890"), 1, 1, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, S("12345678901234567890"), 1, 9, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, S("12345678901234567890"), 1, 18, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, S("12345678901234567890"), 1, 19, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, S("12345678901234567890"), 1, 20, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, S("12345678901234567890"), 10, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, S("12345678901234567890"), 10, 1, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, S("12345678901234567890"), 10, 5, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, S("12345678901234567890"), 10, 9, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, S("12345678901234567890"), 10, 10, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, S("12345678901234567890"), 10, 11, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, S("12345678901234567890"), 19, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, S("12345678901234567890"), 19, 1, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, S("12345678901234567890"), 19, 2, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, S("12345678901234567890"), 20, 0, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, S("12345678901234567890"), 20, 1, S("can't happen"));
+    test(S("abcdefghijklmnopqrst"), 21, S("12345678901234567890"), 21, 0, S("can't happen"));
+}
+
+int main()
+{
+    test0();
+    test1();
+    test2();
+    test3();
+    test4();
+    test5();
+    test6();
+    test7();
+    test8();
+    test9();
+    test10();
+    test11();
+    test12();
+    test13();
+    test14();
+    test15();
+    test16();
+    test17();
+    test18();
+    test19();
+    test20();
+    test21();
+    test22();
+    test23();
+    test24();
+    test25();
+    test26();
+    test27();
+    test28();
+    test29();
+}