[clang-format] Fix end-of-file comments text proto formatting

Summary:
The case of end-of-file comments was formatted badly:
```
key: value
    # end-of-file comment
```
This patch fixes that formatting:
```
key: value
# end-of-file comment
```

Subscribers: cfe-commits

Differential Revision: https://reviews.llvm.org/D48539

llvm-svn: 335449

1 files changed, 12 insertions, 0 deletions

diff --git a/clang/lib/Format/UnwrappedLineParser.cpp b/clang/lib/Format/UnwrappedLineParser.cpp
index e1fa72e84bd..e5afa1264ab 100644
--- a/clang/lib/Format/UnwrappedLineParser.cpp
+++ b/clang/lib/Format/UnwrappedLineParser.cpp
@@ -303,6 +303,18 @@ void UnwrappedLineParser::parseFile() {
   else
     parseLevel(/*HasOpeningBrace=*/false);
   // Make sure to format the remaining tokens.
+  //
+  // LK_TextProto is special since its top-level is parsed as the body of a
+  // braced list, which does not necessarily have natural line separators such
+  // as a semicolon. Comments after the last entry that have been determined to
+  // not belong to that line, as in:
+  //   key: value
+  //   // endfile comment
+  // do not have a chance to be put on a line of their own until this point.
+  // Here we add this newline before end-of-file comments.
+  if (Style.Language == FormatStyle::LK_TextProto &&
+      !CommentsBeforeNextToken.empty())
+    addUnwrappedLine();
   flushComments(true);
   addUnwrappedLine();
 }