Merge pull request #27987 from lupoDharkael/classname-duplicate

Prevent using multiple class_name in a class

modules/gdscript/gdscript_parser.cpp

@@ -3369,7 +3369,7 @@ void GDScriptParser::_parse_extends(ClassNode *p_class) {
 		return;
 	}
 
-	if (!p_class->constant_expressions.empty() || !p_class->subclasses.empty() || !p_class->functions.empty() || !p_class->variables.empty()) {
+	if (!p_class->constant_expressions.empty() || !p_class->subclasses.empty() || !p_class->functions.empty() || !p_class->variables.empty() || p_class->classname_used) {
 
 		_set_error("'extends' must be used before anything else.");
 		return;
@@ -3506,6 +3506,12 @@ void GDScriptParser::_parse_class(ClassNode *p_class) {
 					_set_error("'class_name' syntax: 'class_name <UniqueName>'");
 					return;
 				}
+				if (p_class->classname_used) {
+					_set_error("'class_name' already used for this class.");
+					return;
+				}
+
+				p_class->classname_used = true;
 
 				p_class->name = tokenizer->get_token_identifier(1);
 

modules/gdscript/gdscript_parser.h

@@ -149,6 +149,7 @@ public:
 		bool tool;
 		StringName name;
 		bool extends_used;
+		bool classname_used;
 		StringName extends_file;
 		Vector<StringName> extends_class;
 		DataType base_type;
@@ -198,6 +199,7 @@ public:
 			tool = false;
 			type = TYPE_CLASS;
 			extends_used = false;
+			classname_used = false;
 			end_line = -1;
 			owner = NULL;
 		}