clang-format: Properly reset nested AnnotatedLine structure.

This fixes llvm.org/PR17682.

Without this patch, the following code leads to invalid reads/writes:
  DEBUG({
    return aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa +
           aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa;
  });
  #if a
  #else
  #endif

Because of the #if-#else structure, the code is formatted and annotated
twice and becauce of the nested block, the annotated lines form a
hierarchical structure. This structure was not properly reset between
runs.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@193352 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 1 insertions, 0 deletions

diff --git a/lib/Format/TokenAnnotator.h b/lib/Format/TokenAnnotator.h
index e51003bac8..ca8b115415 100644
--- a/lib/Format/TokenAnnotator.h
+++ b/lib/Format/TokenAnnotator.h
@@ -56,6 +56,7 @@ public:
       Current->Next = I->Tok;
       I->Tok->Previous = Current;
       Current = Current->Next;
+      Current->Children.clear();
       for (SmallVectorImpl<UnwrappedLine>::const_iterator
                I = Node.Children.begin(),
                E = Node.Children.end();