clang-format: Handle trailing commas in column layout of braced list.

Before, this was causing errors.

Also exit early in breakProtrudingToken() (before the expensive call to
SourceManager::getSpellingColumnNumber()). This makes formatting huge
(100k+-item) braced lists possible.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@189094 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Format/ContinuationIndenter.cpp b/lib/Format/ContinuationIndenter.cpp
index 8f7bb50..005eec8 100644
--- a/lib/Format/ContinuationIndenter.cpp
+++ b/lib/Format/ContinuationIndenter.cpp
@@ -569,6 +569,9 @@
 unsigned ContinuationIndenter::breakProtrudingToken(const FormatToken &Current,
                                                     LineState &State,
                                                     bool DryRun) {
+  if (!Current.isOneOf(tok::string_literal, tok::comment))
+    return 0;
+
   llvm::OwningPtr<BreakableToken> Token;
   unsigned StartColumn = State.Column - Current.CodePointCount;
   unsigned OriginalStartColumn =
diff --git a/lib/Format/FormatToken.cpp b/lib/Format/FormatToken.cpp
index 4e232af..1b6d360 100644
--- a/lib/Format/FormatToken.cpp
+++ b/lib/Format/FormatToken.cpp
@@ -92,6 +92,11 @@
   SmallVector<unsigned, 8> EndOfLineItemLength;
 
   for (unsigned i = 0, e = Commas.size() + 1; i != e; ++i) {
+    // If there is a trailing comma in the list, the next item will start at the
+    // closing brace. Don't create an extra item for this.
+    if (ItemBegin == Token->MatchingParen)
+      break;
+
     // Skip comments on their own line.
     while (ItemBegin->HasUnescapedNewline && ItemBegin->isTrailingComment())
       ItemBegin = ItemBegin->Next;