https://bugs.winehq.org/show_bug.cgi?id=42566
--- Comment #2 from Nikolay Sivov bunglehead@gmail.com --- Created attachment 65943 --> https://bugs.winehq.org/attachment.cgi?id=65943 patch
Confirming. Attached patch makes it look better. Remaining issue that text area should be erased regardless, even with empty text. That's probably why erasing code was unusually merged with WM_PAINT originally. This needs more work.