fix bug in SourceColumnMap::startOfPreviousColumn

llvm-svn: 167360

2 files changed, 9 insertions, 1 deletions

diff --git a/clang/lib/Frontend/TextDiagnostic.cpp b/clang/lib/Frontend/TextDiagnostic.cpp
index d622fb35f0f..0eb3d60e0b0 100644
--- a/clang/lib/Frontend/TextDiagnostic.cpp
+++ b/clang/lib/Frontend/TextDiagnostic.cpp
@@ -298,7 +298,7 @@ struct SourceColumnMap {
   /// \brief Map from a byte index to the previous byte which starts a column.
   int startOfPreviousColumn(int N) const {
     assert(0 < N && N < static_cast<int>(m_columnToByte.size()));
-    while (byteToColumn(N--) == -1) {}
+    while (byteToColumn(--N) == -1) {}
     return N;
   }
 
diff --git a/clang/test/Misc/wrong-encoding2.c b/clang/test/Misc/wrong-encoding2.c
new file mode 100644
index 00000000000..43a0f4e900e
--- /dev/null
+++ b/clang/test/Misc/wrong-encoding2.c
@@ -0,0 +1,8 @@
+// RUN: %clang_cc1 -fsyntax-only -fmessage-length 100 %s 2>&1 | FileCheck -strict-whitespace %s
+// REQUIRES: asserts
+
+int main() {
+    "�#x#p)6�)ѽ�$��>U �h����|� থϻg�Y|`?�;;ƿVj�\\����ݪW9���:̊O�E�ېy?SK�y�����i&n";
+}
+
+// CHECK-NOT:Assertion