Warn instad of crashing when class instance is gone after yield. Closes #5247 , probably closes other yield related crashes

1 files changed, 25 insertions, 0 deletions

diff --git a/modules/gdscript/gd_function.cpp b/modules/gdscript/gd_function.cpp
index 6e52686de4..de86eb2ab9 100644
--- a/modules/gdscript/gd_function.cpp
+++ b/modules/gdscript/gd_function.cpp
@@ -846,6 +846,8 @@ Variant GDFunction::call(GDInstance *p_instance, const Variant **p_args, int p_a
 				gdfs->state._class=_class;
 				gdfs->state.ip=ip+ipofs;
 				gdfs->state.line=line;
+				gdfs->state.instance_id=(p_instance && p_instance->get_owner())?p_instance->get_owner()->get_instance_ID():0;
+				gdfs->state.script_id=_class->get_instance_ID();
 				//gdfs->state.result_pos=ip+ipofs-1;
 				gdfs->state.defarg=defarg;
 				gdfs->state.instance=p_instance;
@@ -1352,6 +1354,18 @@ GDFunction::~GDFunction()  {
 
 Variant GDFunctionState::_signal_callback(const Variant** p_args, int p_argcount, Variant::CallError& r_error) {
 
+#ifdef DEBUG_ENABLED
+	if (state.instance_id && !ObjectDB::get_instance(state.instance_id)) {
+		ERR_EXPLAIN("Resumed after yield, but class instance is gone");
+		ERR_FAIL_V(Variant());
+	}
+
+	if (state.script_id && !ObjectDB::get_instance(state.script_id)) {
+		ERR_EXPLAIN("Resumed after yield, but script is gone");
+		ERR_FAIL_V(Variant());
+	}
+#endif
+
 	Variant arg;
 	r_error.error=Variant::CallError::CALL_OK;
 
@@ -1398,6 +1412,17 @@ bool GDFunctionState::is_valid() const {
 Variant GDFunctionState::resume(const Variant& p_arg) {
 
 	ERR_FAIL_COND_V(!function,Variant());
+#ifdef DEBUG_ENABLED
+	if (state.instance_id && !ObjectDB::get_instance(state.instance_id)) {
+		ERR_EXPLAIN("Resumed after yield, but class instance is gone");
+		ERR_FAIL_V(Variant());
+	}
+
+	if (state.script_id && !ObjectDB::get_instance(state.script_id)) {
+		ERR_EXPLAIN("Resumed after yield, but script is gone");
+		ERR_FAIL_V(Variant());
+	}
+#endif
 
 	state.result=p_arg;
 	Variant::CallError err;