[clang-format] Don't change breaking before CtorInitializerColon (#119522)

Don't change breaking before CtorInitializerColon with `ColumnLimit: 0`.

Fixes #119519.

Author: owenca

clang/lib/Format/ContinuationIndenter.cpp

@@ -461,9 +461,8 @@ bool ContinuationIndenter::mustBreak(const LineState &State) {
            getColumnLimit(State) ||
        CurrentState.BreakBeforeParameter) &&
       (!Current.isTrailingComment() || Current.NewlinesBefore > 0) &&
-      (Style.AllowShortFunctionsOnASingleLine != FormatStyle::SFS_All ||
-       Style.BreakConstructorInitializers != FormatStyle::BCIS_BeforeColon ||
-       Style.ColumnLimit != 0)) {
+      (Style.BreakConstructorInitializers != FormatStyle::BCIS_BeforeColon ||
+       Style.ColumnLimit > 0 || Current.NewlinesBefore > 0)) {
     return true;
   }
 

clang/lib/Format/TokenAnnotator.cpp

@@ -492,7 +492,8 @@ class AnnotatingParser {
             ProbablyFunctionType && CurrentToken->Next &&
             (CurrentToken->Next->is(tok::l_paren) ||
              (CurrentToken->Next->is(tok::l_square) &&
-              Line.MustBeDeclaration))) {
+              (Line.MustBeDeclaration ||
+               PrevNonComment->isTypeName(LangOpts))))) {
           OpeningParen.setType(OpeningParen.Next->is(tok::caret)
                                    ? TT_ObjCBlockLParen
                                    : TT_FunctionTypeLParen);

clang/unittests/Format/FormatTest.cpp

@@ -14503,10 +14503,13 @@ TEST_F(FormatTest, PullTrivialFunctionDefinitionsIntoSingleLine) {
   FormatStyle DoNotMergeNoColumnLimit = NoColumnLimit;
   DoNotMergeNoColumnLimit.AllowShortFunctionsOnASingleLine =
       FormatStyle::SFS_None;
-  verifyFormat("A()\n"
-               "    : b(0) {\n"
+  verifyFormat("A() : b(0) {\n"
                "}",
-               "A():b(0){}", DoNotMergeNoColumnLimit);
+               DoNotMergeNoColumnLimit);
+  verifyNoChange("A()\n"
+                 "    : b(0) {\n"
+                 "}",
+                 DoNotMergeNoColumnLimit);
   verifyFormat("A()\n"
                "    : b(0) {\n"
                "}",