[clang-format] Fix crash in TokenAnnotator #82349

Squash commit from llvm/llvm-project#82349

Change-Id: Ie2a8d501486f2132e5ab9db57159a01f1b631fec

Author: cristianadam

clang/lib/Format/TokenAnnotator.cpp

@@ -3513,7 +3513,7 @@ void TokenAnnotator::calculateFormattingInformation(AnnotatedLine &Line) const {
         do {
           Tok = Tok->Next;
         } while (Tok && Tok->isNot(TT_OverloadedOperatorLParen));
-        if (!Tok)
+        if (!Tok || !Tok->MatchingParen)
           break;
         const auto *LeftParen = Tok;
         for (Tok = Tok->Next; Tok && Tok != LeftParen->MatchingParen;

clang/unittests/Format/FormatTest.cpp

@@ -13422,6 +13422,12 @@ TEST_F(FormatTest, IncorrectCodeUnbalancedBraces) {
   verifyFormat("{");
   verifyFormat("#})");
   verifyNoCrash("(/**/[:!] ?[).");
+  verifyNoCrash("struct X {\n"
+                "  operator iunt(\n"
+                "};");
+  verifyNoCrash("struct Foo {\n"
+                "  operator foo(bar\n"
+                "};");
 }
 
 TEST_F(FormatTest, IncorrectUnbalancedBracesInMacrosWithUnicode) {