Fix a bug in the line merging.

If the first line of a merge would exactly fit into the column limit,
an unsigned overflow made us not break.

llvm-svn: 172426

2 files changed, 4 insertions, 0 deletions

diff --git a/clang/lib/Format/Format.cpp b/clang/lib/Format/Format.cpp
index 742b9a8d1cc..4e9fd405df3 100644
--- a/clang/lib/Format/Format.cpp
+++ b/clang/lib/Format/Format.cpp
@@ -1408,6 +1408,8 @@ private:
     unsigned Length = 0;
     if (!fitsIntoLimit(I->First, Limit, &Length))
       return false;
+    if (Limit == Length)
+      return true; // Couldn't fit a space.
     Limit -= Length + 1; // One space.
     if (I + 1 == E)
       return true;
diff --git a/clang/unittests/Format/FormatTest.cpp b/clang/unittests/Format/FormatTest.cpp
index daebc4ddab1..8e55ddb5d0f 100644
--- a/clang/unittests/Format/FormatTest.cpp
+++ b/clang/unittests/Format/FormatTest.cpp
@@ -138,6 +138,8 @@ TEST_F(FormatTest, FormatIfWithoutCompountStatement) {
                "  f();");
   verifyFormat("if (a) return;", getLLVMStyleWithColumns(14));
   verifyFormat("if (a)\n  return;", getLLVMStyleWithColumns(13));
+  verifyFormat("if (aaaaaaaaa)\n"
+               "  return;", getLLVMStyleWithColumns(14));
 }
 
 TEST_F(FormatTest, ParseIfElse) {