only truncate source lines in text diagnostics when

the ellipsis is shorter than the text it replaces

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@167364 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Frontend/TextDiagnostic.cpp

@@ -494,7 +494,7 @@ static void selectInterestingSourceRegion(std::string &SourceLine,
 
   // The line needs some trunctiona, and we'd prefer to keep the front
   //  if possible, so remove the back
-  if (BackColumnsRemoved)
+  if (BackColumnsRemoved > strlen(back_ellipse))
     SourceLine.replace(SourceEnd, std::string::npos, back_ellipse);
 
   // If that's enough then we're done
@@ -502,7 +502,7 @@ static void selectInterestingSourceRegion(std::string &SourceLine,
     return;
 
   // Otherwise remove the front as well
-  if (FrontColumnsRemoved) {
+  if (FrontColumnsRemoved > strlen(front_ellipse)) {
     SourceLine.replace(0, SourceStart, front_ellipse);
     CaretLine.replace(0, CaretStart, front_space);
     if (!FixItInsertionLine.empty())

test/Misc/unnecessary-elipses.cpp

@@ -0,0 +1,15 @@
+// RUN: %clang_cc1 -fsyntax-only -fmessage-length 80 %s 2>&1 | FileCheck -strict-whitespace %s
+
+int main() {
+    "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx";
+// CHECK: {{^    "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx";}}
+
+        "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx";
+// CHECK: {{^  ..."xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx";}}
+
+"xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"        ;
+// CHECK: {{^"xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"...}}
+
+        "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"        ;
+// CHECK: {{^  ..."xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"...}}
+}