don't step into the middle of multibyte sequences

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@167361 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 2 insertions, 2 deletions

diff --git a/lib/Frontend/TextDiagnostic.cpp b/lib/Frontend/TextDiagnostic.cpp
index 0eb3d60e0b..ca55197f90 100644
--- a/lib/Frontend/TextDiagnostic.cpp
+++ b/lib/Frontend/TextDiagnostic.cpp
@@ -418,7 +418,7 @@ static void selectInterestingSourceRegion(std::string &SourceLine,
     bool ExpandedRegion = false;
 
     if (SourceStart>0) {
-      unsigned NewStart = SourceStart-1;
+      unsigned NewStart = map.startOfPreviousColumn(SourceStart);
 
       // Skip over any whitespace we see here; we're looking for
       // another bit of interesting text.
@@ -445,7 +445,7 @@ static void selectInterestingSourceRegion(std::string &SourceLine,
     }
 
     if (SourceEnd<SourceLine.size()) {
-      unsigned NewEnd = SourceEnd+1;
+      unsigned NewEnd = map.startOfNextColumn(SourceEnd);
 
       // Skip over any whitespace we see here; we're looking for
       // another bit of interesting text.