diff --git a/lib/AST/RawCommentList.cpp b/lib/AST/RawCommentList.cpp
index 78164593806983bbe1c474ebb8b913cb89836f1a..fb85c142e3f99d7369e29eb58ec36a51032aa5c6 100644
--- a/lib/AST/RawCommentList.cpp
+++ b/lib/AST/RawCommentList.cpp
@@ -21,8 +21,10 @@ using namespace clang;
 
 namespace {
 /// Get comment kind and bool describing if it is a trailing comment.
-std::pair<RawComment::CommentKind, bool> getCommentKind(StringRef Comment) {
-  if (Comment.size() < 3 || Comment[0] != '/')
+std::pair<RawComment::CommentKind, bool> getCommentKind(StringRef Comment,
+                                                        bool ParseAllComments) {
+  const size_t MinCommentLength = ParseAllComments ? 2 : 3;
+  if ((Comment.size() < MinCommentLength) || Comment[0] != '/')
     return std::make_pair(RawComment::RCK_Invalid, false);
 
   RawComment::CommentKind K;
@@ -76,7 +78,7 @@ RawComment::RawComment(const SourceManager &SourceMgr, SourceRange SR,
 
   if (!Merged) {
     // Guess comment kind.
-    std::pair<CommentKind, bool> K = getCommentKind(RawText);
+    std::pair<CommentKind, bool> K = getCommentKind(RawText, ParseAllComments);
     Kind = K.first;
     IsTrailingComment = K.second;
 
diff --git a/test/Index/parse-all-comments.c b/test/Index/parse-all-comments.c
index ac31f5b74e17ed6e5e9f7f8dfeaebd85ecbb2067..f8b0449f200206c80e6c4c34099113823dfae95b 100644
--- a/test/Index/parse-all-comments.c
+++ b/test/Index/parse-all-comments.c
@@ -28,6 +28,11 @@ void isdoxy6(void);
 /** But there are other blocks that are part of the comment, too.  IS_DOXYGEN_END */
 void multi_line_comment_plus_ordinary(int);
 
+// MULTILINE COMMENT
+//
+// WITH EMPTY LINE
+void multi_line_comment_empty_line(int);
+
 #endif
 
 // RUN: rm -rf %t
@@ -54,3 +59,4 @@ void multi_line_comment_plus_ordinary(int);
 // CHECK: parse-all-comments.c:19:6: FunctionDecl=isdoxy5:{{.*}} isdoxy5 IS_DOXYGEN_SINGLE
 // CHECK: parse-all-comments.c:22:6: FunctionDecl=isdoxy6:{{.*}} isdoxy6 IS_DOXYGEN_SINGLE
 // CHECK: parse-all-comments.c:29:6: FunctionDecl=multi_line_comment_plus_ordinary:{{.*}} BLOCK_ORDINARY_COMMENT {{.*}} ORDINARY COMMENT {{.*}} IS_DOXYGEN_START {{.*}} IS_DOXYGEN_END
+// CHECK: parse-all-comments.c:34:6: FunctionDecl=multi_line_comment_empty_line:{{.*}} MULTILINE COMMENT{{.*}}\n{{.*}}\n{{.*}} WITH EMPTY LINE