fix segfault (because of erasing after the vector boundaries) when the cached token position is at the end
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@77159 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Lex/PPCaching.cpp b/lib/Lex/PPCaching.cpp
index 53aa09c..8087878 100644
--- a/lib/Lex/PPCaching.cpp
+++ b/lib/Lex/PPCaching.cpp
@@ -102,7 +102,8 @@
assert((BacktrackPositions.empty() || BacktrackPositions.back() < i) &&
"The backtrack pos points inside the annotated tokens!");
// Replace the cached tokens with the single annotation token.
- CachedTokens.erase(AnnotBegin + 1, CachedTokens.begin() + CachedLexPos);
+ if (i < CachedLexPos)
+ CachedTokens.erase(AnnotBegin + 1, CachedTokens.begin() + CachedLexPos);
*AnnotBegin = Tok;
CachedLexPos = i;
return;