[clang-format] Re-align broken comment lines where appropriate.

Summary:
The comment aligner was skipping over newly broken comment lines. This patch fixes that.

source:
```
int ab; // line
int a; // long long
```

format with column limit 15 before:
```
int ab; // line
int a;  // long
       // long
```

format with column limit 15 after:
```
int ab; // line
int a;  // long
        // long
```

Reviewers: djasper

Reviewed By: djasper

Subscribers: cfe-commits, klimek

Differential Revision: https://reviews.llvm.org/D29486

llvm-svn: 293997

1 files changed, 34 insertions, 0 deletions

diff --git a/clang/unittests/Format/FormatTest.cpp b/clang/unittests/Format/FormatTest.cpp
index d9f56e38f84..6cc9d1979fa 100644
--- a/clang/unittests/Format/FormatTest.cpp
+++ b/clang/unittests/Format/FormatTest.cpp
@@ -11852,6 +11852,40 @@ TEST_F(FormatTest, AlignTrailingComments) {
                    "             // line 3\n"
                    "          b);",
                    getLLVMStyleWithColumns(40)));
+
+  // Align newly broken trailing comments.
+  EXPECT_EQ("int ab; // line\n"
+            "int a;  // long\n"
+            "        // long\n",
+            format("int ab; // line\n"
+                   "int a; // long long\n",
+                   getLLVMStyleWithColumns(15)));
+  EXPECT_EQ("int ab; // line\n"
+            "int a;  // long\n"
+            "        // long\n"
+            "        // long",
+            format("int ab; // line\n"
+                   "int a; // long long\n"
+                   "       // long",
+                   getLLVMStyleWithColumns(15)));
+  EXPECT_EQ("int ab; // line\n"
+            "int a;  // long\n"
+            "        // long\n"
+            "pt c;   // long",
+            format("int ab; // line\n"
+                   "int a; // long long\n"
+                   "pt c; // long",
+                   getLLVMStyleWithColumns(15)));
+  EXPECT_EQ("int ab; // line\n"
+            "int a;  // long\n"
+            "        // long\n"
+            "\n"
+            "// long",
+            format("int ab; // line\n"
+                   "int a; // long long\n"
+                   "\n"
+                   "// long",
+                   getLLVMStyleWithColumns(15)));
 }
 } // end namespace
 } // end namespace format