Fix another clang-format crasher related to multi-line comments.

This fixes:
/*
*
* something long going over the column limit.
*/

llvm-svn: 182932

clang/lib/Format/BreakableToken.cpp

@@ -241,6 +241,9 @@ BreakableBlockComment::BreakableBlockComment(const FormatStyle &Style,
       Lines[i] = Lines[i].substr(Offset);
       LeadingWhitespace[i] += Offset;
     }
+    // Exclude empty lines from the calculation of the left-most column.
+    if (Lines[i].empty())
+      continue;
     IndentAtLineBreak = std::min<int>(IndentAtLineBreak, StartOfLineColumn[i]);
   }
   DEBUG({

clang/unittests/Format/FormatTest.cpp

@@ -3641,6 +3641,17 @@ TEST_F(FormatTest, BlockComments) {
                    "/* */someCall(parameter);",
                    getLLVMStyleWithColumns(15)));
   EXPECT_EQ("/*\n**\n*/", format("/*\n**\n*/"));
+  // FIXME: Consider whether empty lines can dictated the left-most column.
+  EXPECT_EQ("/*\n"
+            "*\n"
+            " * aaaaaa\n"
+            " * aaaaaa\n"
+            "*/",
+            format("/*\n"
+                   "*\n"
+                   " * aaaaaa aaaaaa\n"
+                   "*/",
+                   getLLVMStyleWithColumns(10)));
 
   FormatStyle NoBinPacking = getLLVMStyle();
   NoBinPacking.BinPackParameters = false;