[#22831] transform problem with hidden parent object

Partial fix. It now checks if selected parents are modifiable (due to the look up for base, this could get slow, but no other good way to do it).

source/blender/editors/transform/transform_conversions.c

@@ -4371,7 +4371,11 @@ static void set_trans_object_base_flags(bContext *C, TransInfo *t)
 
 			/* if parent selected, deselect */
 			while(parsel) {
-				if(parsel->flag & SELECT) break;
+				if(parsel->flag & SELECT) {
+					Base *parbase = object_in_scene(parsel, scene);
+					if TESTBASELIB_BGMODE(v3d, scene, parbase)
+							break;
+				}
 				parsel= parsel->parent;
 			}