Mark Jansen (@learn-more) commented about dlls/user32/edit.c:
if (!dx) { /* force scroll info update */ EDIT_UpdateScrollInfo(es);
EDIT_NOTIFY_PARENT(es, EN_HSCROLL);
notify_parent(es, EN_HSCROLL);
The code below only uses `es` under the guard of `if (dx)`, but when code below is edited this case most likely won't be updated, so it would be safer to bail out here as well.