-bit slower execution in debug, but proper error reporting for get index and operators, fixes #1911

modules/gdscript/gd_script.cpp

@@ -335,17 +335,26 @@ Variant GDFunction::call(GDInstance *p_instance, const Variant **p_args, int p_a
 				GET_VARIANT_PTR(b,3);
 				GET_VARIANT_PTR(dst,4);
 
+#ifdef DEBUG_ENABLED
+				Variant ret;
+				Variant::evaluate(op,*a,*b,ret,valid);
+#else
 				Variant::evaluate(op,*a,*b,*dst,valid);
+#endif
+
 				if (!valid) {
-					if (dst->get_type()==Variant::STRING) {
+					if (ret.get_type()==Variant::STRING) {
 						//return a string when invalid with the error
-						err_text=*dst;
+						err_text=ret;
 						err_text += " in operator '"+Variant::get_operator_name(op)+"'.";
 					} else {
 						err_text="Invalid operands '"+Variant::get_type_name(a->get_type())+"' and '"+Variant::get_type_name(b->get_type())+"' in operator '"+Variant::get_operator_name(op)+"'.";
 					}
 					break;
 				}
+#ifdef DEBUG_ENABLED
+				*dst=ret;
+#endif
 
 				ip+=5;
 
@@ -457,8 +466,13 @@ Variant GDFunction::call(GDInstance *p_instance, const Variant **p_args, int p_a
 				GET_VARIANT_PTR(dst,3);
 
 				bool valid;
+#ifdef DEBUG_ENABLED
+//allow better error message in cases where src and dst are the same stack position
+				Variant ret = src->get(*index,&valid);
+#else
 				*dst = src->get(*index,&valid);
 
+#endif
 				if (!valid) {
 					String v = index->operator String();
 					if (v!="") {
@@ -469,6 +483,9 @@ Variant GDFunction::call(GDInstance *p_instance, const Variant **p_args, int p_a
 					err_text="Invalid get index "+v+" (on base: '"+_get_var_type(src)+"').";
 					break;
 				}
+#ifdef DEBUG_ENABLED
+				*dst=ret;
+#endif
 				ip+=4;
 			} continue;
 			case OPCODE_SET_NAMED: {
@@ -508,7 +525,13 @@ Variant GDFunction::call(GDInstance *p_instance, const Variant **p_args, int p_a
 				const StringName *index = &_global_names_ptr[indexname];
 
 				bool valid;
+#ifdef DEBUG_ENABLED
+//allow better error message in cases where src and dst are the same stack position
+				Variant ret = src->get_named(*index,&valid);
+
+#else
 				*dst = src->get_named(*index,&valid);
+#endif
 
 				if (!valid) {
 					if (src->has_method(*index)) {
@@ -518,7 +541,9 @@ Variant GDFunction::call(GDInstance *p_instance, const Variant **p_args, int p_a
 					}
 					break;
 				}
-
+#ifdef DEBUG_ENABLED
+				*dst=ret;
+#endif
 				ip+=4;
 			} continue;
 			case OPCODE_ASSIGN: {