[clang] AST Visitor: skip empty qualifiers in QualifiedTemplateName (#93926)

Author: mizvekov

clang/include/clang/AST/RecursiveASTVisitor.h

@@ -855,10 +855,14 @@ bool RecursiveASTVisitor<Derived>::TraverseDeclarationNameInfo(
 
 template <typename Derived>
 bool RecursiveASTVisitor<Derived>::TraverseTemplateName(TemplateName Template) {
-  if (DependentTemplateName *DTN = Template.getAsDependentTemplateName())
+  if (DependentTemplateName *DTN = Template.getAsDependentTemplateName()) {
     TRY_TO(TraverseNestedNameSpecifier(DTN->getQualifier()));
-  else if (QualifiedTemplateName *QTN = Template.getAsQualifiedTemplateName())
-    TRY_TO(TraverseNestedNameSpecifier(QTN->getQualifier()));
+  } else if (QualifiedTemplateName *QTN =
+                 Template.getAsQualifiedTemplateName()) {
+    if (QTN->getQualifier()) {
+      TRY_TO(TraverseNestedNameSpecifier(QTN->getQualifier()));
+    }
+  }
 
   return true;
 }