From 854ca794c17679ba4d0e529e8eb8b6b3703d1984 Mon Sep 17 00:00:00 2001
From: Manuel Klimek <klimek@google.com>
Date: Thu, 23 May 2013 20:46:07 +0000
Subject: [PATCH] Fix aligning of comments.

Previously we started sequences to align for single line comments when
the previous line had a trailing comment, but the sequence was broken
for other reasons.

Now we re-format:
// a
 // b
f(); // c
to:
// a
// b
f(); // c

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@182608 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Format/WhitespaceManager.cpp |  9 +++++----
 unittests/Format/FormatTest.cpp  | 20 ++++++++++++++++++++
 2 files changed, 25 insertions(+), 4 deletions(-)

diff --git a/lib/Format/WhitespaceManager.cpp b/lib/Format/WhitespaceManager.cpp
index e6c363b373..f7b65fc72c 100644
--- a/lib/Format/WhitespaceManager.cpp
+++ b/lib/Format/WhitespaceManager.cpp
@@ -170,10 +170,11 @@ void WhitespaceManager::alignTrailingComments() {
         MinColumn = std::max(MinColumn, ChangeMinColumn);
         MaxColumn = std::min(MaxColumn, ChangeMaxColumn);
       }
-      BreakBeforeNext = (i == 0) || (Changes[i].NewlinesBefore > 1) ||
-                        (Changes[i].NewlinesBefore == 1 &&
-                         !Changes[i - 1].IsTrailingComment) ||
-                        WasAlignedWithStartOfNextLine;
+      BreakBeforeNext =
+          (i == 0) || (Changes[i].NewlinesBefore > 1) ||
+          // Never start a sequence with a comment at the beginning of
+          // the line.
+          (Changes[i].NewlinesBefore == 1 && StartOfSequence == i);
       Newlines = 0;
     }
   }
diff --git a/unittests/Format/FormatTest.cpp b/unittests/Format/FormatTest.cpp
index 5346bdc757..ce551e9d1b 100644
--- a/unittests/Format/FormatTest.cpp
+++ b/unittests/Format/FormatTest.cpp
@@ -657,6 +657,26 @@ TEST_F(FormatTest, UnderstandsSingleLineComments) {
             format("lineWith();   // comment\n"
                    "// at start\n"
                    "otherLine();   // comment"));
+  EXPECT_EQ("lineWith();\n"
+            "// at start\n"
+            "otherLine(); // comment",
+            format("lineWith();\n"
+                   " // at start\n"
+                   "otherLine();   // comment"));
+  EXPECT_EQ("// first\n"
+            "// at start\n"
+            "otherLine(); // comment",
+            format("// first\n"
+                   " // at start\n"
+                   "otherLine();   // comment"));
+  EXPECT_EQ("f();\n"
+            "// first\n"
+            "// at start\n"
+            "otherLine(); // comment",
+            format("f();\n"
+                   "// first\n"
+                   " // at start\n"
+                   "otherLine();   // comment"));
 }
 
 TEST_F(FormatTest, CanFormatCommentsLocally) {
-- 
2.50.1