clang-format: Row back on the AlwaysBreakBeforeMultilineStrings change.

It was a bit too aggressive.

With this patch, we keep on breaking here:
  aaaaaaaaaaaaa(aaaaaaa,
                "aaaaaaa"
                "bbbbbbb");

But don't break in:
  aaaaaaaaaaaaa(aaaaaaa, aaaaaaaa("aaaaaaa"
                                  "bbbbbbb"));

llvm-svn: 240024

clang/lib/Format/ContinuationIndenter.cpp

@@ -169,7 +169,8 @@ bool ContinuationIndenter::mustBreak(const LineState &State) {
     return false;
 
   if (Style.AlwaysBreakBeforeMultilineStrings &&
-      NewLineColumn == State.FirstIndent + Style.ContinuationIndentWidth &&
+      (NewLineColumn == State.FirstIndent + Style.ContinuationIndentWidth ||
+       Previous.is(tok::comma)) &&
       !Previous.isOneOf(tok::kw_return, tok::lessless, tok::at) &&
       !Previous.isOneOf(TT_InlineASMColon, TT_ConditionalExpr) &&
       nextIsMultilineString(State))

clang/unittests/Format/FormatTest.cpp

@@ -4647,12 +4647,17 @@ TEST_F(FormatTest, AlwaysBreakBeforeMultilineStrings) {
   verifyFormat("aaaa(qqq, \"bbbb\"\n"
                "          \"cccc\");",
                NoBreak);
-  verifyFormat("aaaa(qqq, \"bbbb\"\n"
+  verifyFormat("aaaa(qqq,\n"
+               "     \"bbbb\"\n"
                "     \"cccc\");",
                Break);
-  verifyFormat("aaaa(qqq, L\"bbbb\"\n"
+  verifyFormat("aaaa(qqq,\n"
+               "     L\"bbbb\"\n"
                "     L\"cccc\");",
                Break);
+  verifyFormat("aaaaa(aaaaaa, aaaaaaa(\"aaaa\"\n"
+               "                      \"bbbb\"));",
+               Break);
 
   // As we break before unary operators, breaking right after them is bad.
   verifyFormat("string foo = abc ? \"x\"\n"