[Frontend] Don't index into an empty string.

Found by msan! llvm-svn: 303686
2017-05-23 20:48:21 +00:00 · 2017-05-23 20:48:21 +00:00 · 4e382f9ee9
parent f43ece3ff5
commit 4e382f9ee9
1 changed files with 1 additions and 1 deletions
--- a/clang/lib/Frontend/TextDiagnostic.cpp
+++ b/clang/lib/Frontend/TextDiagnostic.cpp
@ -1252,7 +1252,7 @@ void TextDiagnostic::emitSnippetAndCaret(
    }

    // Finally, remove any blank spaces from the end of CaretLine.
-    while (CaretLine[CaretLine.size() - 1] == ' ')
+    while (!CaretLine.empty() && CaretLine[CaretLine.size() - 1] == ' ')
      CaretLine.erase(CaretLine.end() - 1);

    // Emit what we have computed.