After years of telling people: 'If you ever find any of my code that self-move-assigns, send me a bug report.' Somebody finally took me up on it. vector::erase(begin(), begin()) does a self-move-assign of every element in the vector, leaving all of those elements in an unspecified state. I checked the other containers for this same bug and did not find it. Added test case.

llvm-svn: 179760

2 files changed, 9 insertions, 1 deletions

diff --git a/libcxx/include/vector b/libcxx/include/vector
index d1bc23e6a81..e04c2673b2e 100644
--- a/libcxx/include/vector
+++ b/libcxx/include/vector
@@ -1615,7 +1615,8 @@ vector<_Tp, _Allocator>::erase(const_iterator __first, const_iterator __last)
     _LIBCPP_ASSERT(__first <= __last, "vector::erase(first, last) called with invalid range");
     pointer __p = this->__begin_ + (__first - begin());
     iterator __r = __make_iter(__p);
-    this->__destruct_at_end(_VSTD::move(__p + (__last - __first), this->__end_, __p));
+    if (__first != __last)
+        this->__destruct_at_end(_VSTD::move(__p + (__last - __first), this->__end_, __p));
     return __r;
 }
 
diff --git a/libcxx/test/containers/sequences/vector/vector.modifiers/erase_iter_iter.pass.cpp b/libcxx/test/containers/sequences/vector/vector.modifiers/erase_iter_iter.pass.cpp
index 1185412adcb..5fdcb8775b5 100644
--- a/libcxx/test/containers/sequences/vector/vector.modifiers/erase_iter_iter.pass.cpp
+++ b/libcxx/test/containers/sequences/vector/vector.modifiers/erase_iter_iter.pass.cpp
@@ -47,4 +47,11 @@ int main()
         assert(distance(l1.cbegin(), l1.cend()) == 0);
         assert(i == l1.begin());
     }
+    {
+        std::vector<std::vector<int> > outer(2, std::vector<int>(1));
+        outer.erase(outer.begin(), outer.begin());
+        assert(outer.size() == 2);
+        assert(outer[0].size() == 1);
+        assert(outer[1].size() == 1);
+    }
 }