clang-format: Fix corner case for string splitting ..

.. in conjunction with Style.AlwaysBreakBeforeMultilineStrings. Also,
simplify the implementation by handling newly split strings and already
split strings by the same code.

llvm-svn: 189102
diff --git a/clang/unittests/Format/FormatTest.cpp b/clang/unittests/Format/FormatTest.cpp
index 94d7b34..aec93bb 100644
--- a/clang/unittests/Format/FormatTest.cpp
+++ b/clang/unittests/Format/FormatTest.cpp
@@ -5265,6 +5265,12 @@
             format("llvm::outs() << "
                    "\"aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaa"
                    "aaaaaaaaaaaaaaaaaaa\";"));
+  EXPECT_EQ("ffff(\n"
+            "    {\"aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa \"\n"
+            "     \"aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa\"});",
+            format("ffff({\"aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa "
+                   "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa\"});",
+                   getGoogleStyle()));
 
   FormatStyle AlignLeft = getLLVMStyleWithColumns(12);
   AlignLeft.AlignEscapedNewlinesLeft = true;