1 files changed, 36 insertions, 8 deletions

diff --git a/modules/gdscript/gdscript.cpp b/modules/gdscript/gdscript.cpp
index cdd5deb7ee..8559fac57c 100644
--- a/modules/gdscript/gdscript.cpp
+++ b/modules/gdscript/gdscript.cpp
@@ -376,10 +376,15 @@ void GDScript::_update_exports_values(Map<StringName, Variant> &values, List<Pro
 }
 #endif
 
-bool GDScript::_update_exports() {
+bool GDScript::_update_exports(bool *r_err, bool p_recursive_call) {
 
 #ifdef TOOLS_ENABLED
 
+	static Vector<GDScript *> base_caches;
+	if (!p_recursive_call)
+		base_caches.clear();
+	base_caches.append(this);
+
 	bool changed = false;
 
 	if (source_changed_cache) {
@@ -473,7 +478,22 @@ bool GDScript::_update_exports() {
 	placeholder_fallback_enabled = false;
 
 	if (base_cache.is_valid() && base_cache->is_valid()) {
-		if (base_cache->_update_exports()) {
+		for (int i = 0; i < base_caches.size(); i++) {
+			if (base_caches[i] == base_cache.ptr()) {
+				if (r_err)
+					*r_err = true;
+				valid = false; // to show error in the editor
+				base_cache->valid = false;
+				base_cache->inheriters_cache.clear(); // to prevent future stackoverflows
+				base_cache.unref();
+				base.unref();
+				_base = nullptr;
+				ERR_FAIL_V_MSG(false, "Cyclic inheritance in script class.");
+			}
+		}
+		if (base_cache->_update_exports(r_err, true)) {
+			if (r_err && *r_err)
+				return false;
 			changed = true;
 		}
 	}
@@ -501,7 +521,10 @@ void GDScript::update_exports() {
 
 #ifdef TOOLS_ENABLED
 
-	_update_exports();
+	bool cyclic_error = false;
+	_update_exports(&cyclic_error);
+	if (cyclic_error)
+		return;
 
 	Set<ObjectID> copy = inheriters_cache; //might get modified
 
@@ -635,12 +658,14 @@ uint16_t GDScript::get_rpc_method_id(const StringName &p_method) const {
 }
 
 StringName GDScript::get_rpc_method(const uint16_t p_rpc_method_id) const {
-	if (p_rpc_method_id >= rpc_functions.size()) return StringName();
+	if (p_rpc_method_id >= rpc_functions.size())
+		return StringName();
 	return rpc_functions[p_rpc_method_id].name;
 }
 
 MultiplayerAPI::RPCMode GDScript::get_rpc_mode_by_id(const uint16_t p_rpc_method_id) const {
-	if (p_rpc_method_id >= rpc_functions.size()) return MultiplayerAPI::RPC_MODE_DISABLED;
+	if (p_rpc_method_id >= rpc_functions.size())
+		return MultiplayerAPI::RPC_MODE_DISABLED;
 	return rpc_functions[p_rpc_method_id].mode;
 }
 
@@ -662,12 +687,14 @@ uint16_t GDScript::get_rset_property_id(const StringName &p_variable) const {
 }
 
 StringName GDScript::get_rset_property(const uint16_t p_rset_member_id) const {
-	if (p_rset_member_id >= rpc_variables.size()) return StringName();
+	if (p_rset_member_id >= rpc_variables.size())
+		return StringName();
 	return rpc_variables[p_rset_member_id].name;
 }
 
 MultiplayerAPI::RPCMode GDScript::get_rset_mode_by_id(const uint16_t p_rset_member_id) const {
-	if (p_rset_member_id >= rpc_variables.size()) return MultiplayerAPI::RPC_MODE_DISABLED;
+	if (p_rset_member_id >= rpc_variables.size())
+		return MultiplayerAPI::RPC_MODE_DISABLED;
 	return rpc_variables[p_rset_member_id].mode;
 }
 
@@ -2157,7 +2184,8 @@ String GDScriptWarning::get_message() const {
 		case STANDALONE_TERNARY: {
 			return "Standalone ternary conditional operator: the return value is being discarded.";
 		}
-		case WARNING_MAX: break; // Can't happen, but silences warning
+		case WARNING_MAX:
+			break; // Can't happen, but silences warning
 	}
 	ERR_FAIL_V_MSG(String(), "Invalid GDScript warning code: " + get_name_from_code(code) + ".");