[clang-format] Fix weird handling of AfterColon

[HazardyKnusperkeks]

Summary

This fixes https://github.com/llvm/llvm-project/issues/64895.

[HazardyKnusperkeks]

clang/unittests/Format/FormatTest.cpp

7993–7994

I know we usually don't change existing tests. But I sincerely think this a bug. From the documentation I don't see any reason why there should be a line break.

[owenpan]

clang/unittests/Format/FormatTest.cpp

7954

loooooooooooooooooooong?

7993–7997

Shorten the ctor name so that we don't have to split the line.

[HazardyKnusperkeks]

Will be fixed on commit.

clang/lib/Format/ContinuationIndenter.cpp

unsigned ContinuationIndenter::moveStateToNextToken(LineState &State,
   }
   if (Current.is(TT_CtorInitializerColon) &&
       Style.BreakConstructorInitializers == FormatStyle::BCIS_AfterColon) {
     CurrentState.Indent =
         State.FirstIndent + Style.ConstructorInitializerIndentWidth;
     CurrentState.NestedBlockIndent = CurrentState.Indent;
     if (Style.PackConstructorInitializers > FormatStyle::PCIS_BinPack)
       CurrentState.AvoidBinPacking = true;
+    else
+      CurrentState.BreakBeforeParameter = false;
   }
   if (Current.is(TT_InheritanceColon)) {
     CurrentState.Indent =
         State.FirstIndent + Style.ConstructorInitializerIndentWidth;
   }
   if (Current.isOneOf(TT_BinaryOperator, TT_ConditionalExpr) && Newline)
     CurrentState.NestedBlockIndent = State.Column + Current.ColumnWidth + 1;
   if (Current.isOneOf(TT_LambdaLSquare, TT_LambdaArrow))

clang/unittests/Format/FormatTest.cpp

verifyFormat("Constructor() :\n"
                getStyleWithColumns(Style, 44));
   verifyFormat("Constructor() :\n"
                "    Initializer(FitsOnTheLine) {}",
                getStyleWithColumns(Style, 43));
 
   verifyFormat("template <typename T>\n"
                "Constructor() : Initializer(FitsOnTheLine) {}",
                getStyleWithColumns(Style, 50));
+  verifyFormat(
+      "Class::Class(int some, int arguments, int loooooooooooooooooooong,\n"
+      "             int mooooooooooooore) noexcept :\n"
+      "    Super{some, arguments}, Member{5}, Member2{2} {}",
+      Style);
   Style.PackConstructorInitializers = FormatStyle::PCIS_NextLine;
   verifyFormat(
       "SomeClass::Constructor() :\n"
       "    aaaaaaaaaaaaa(aaaaaaaaaaaaaa), aaaaaaaaaaaaaaa(aaaaaaaaaaaa) {}",
       Style);
   verifyFormat(
       "SomeClass::Constructor() : // NOLINT\n"
       "    aaaaaaaaaaaaa(aaaaaaaaaaaaaa), aaaaaaaaaaaaaaa(aaaaaaaaaaaa) {}",
verifyFormat(
       "SomeClass::Constructor() :\n"
       "    aaaaaaaaaaaaa(aaaaaaaaaaaaaa), aaaaaaaaaaaaa(aaaaaaaaaaaaaa),\n"
       "    aaaaaaaaaaaaa(aaaaaaaaaaaaaa) {}",
       Style);
   verifyFormat(
       "SomeClass::Constructor() :\n"
       "    aaaaaaaaaaaaaaaaaaaaaaaaaaaaaa(aaaaaaaaaaaaaaaaaaaaaaaaaaaaaa),\n"
       "    aaaaaaaaaaaaaaa(aaaaaaaaaaaa) {}",
       Style);
-  verifyFormat("Constructor(aaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa,\n"
-               "            aaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa) :\n"
-               "    aaaaaaaaaa(aaaaaa) {}",
-               Style);
+  verifyFormat(
+      "Ctor(aaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa,\n"
+      "     aaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa) : aaaaaaaaaa(aaaaaa) {}",
 
   verifyFormat("Constructor() :\n"
                "    aaaaaaaaaaaaaaaaaaaaaaaa(aaaaaaaaaaaaaaaaaaaaaaaaaaa),\n"
                "    aaaaaaaaaaaaaaaaaaaaaaaa(aaaaaaaaaaaaaaaaaaaaaaaaaaa,\n"
                "                             aaaaaaaaaaaaaaaaaaaaaaaaaaa),\n"
                "    aaaaaaaaaaaaaaaaaaaaaaa() {}",
                Style);