[Bug 2057] When textbox is told to scroll to end of text, it doesn't

http://bugs.winehq.org/show_bug.cgi?id=2057

--- Comment #14 from Dylan Smith   2008-10-17 12:46:30 ---
Created an attachment (id=16711)
 --> (http://bugs.winehq.org/attachment.cgi?id=16711)
richedit: Added test for auto y scroll behaviour with redraw disabled.

This test shows that my previous patch is not a proper fix, like I expected. 
The problem extends to the fact that the scrollable area is not being updated
properly with redraw disabled, so even though ME_EnsureVisible is called, it
will still not scroll all the way to the bottom.

This can be seen in eMule's log with the patch applied, since it will scroll to
one line from the end of the text (which isn't an issue in this case since the
last line is blank).

It seems like the proper fix will make sure that everything is updated with
redraw disabled, while avoiding actually repainting the screen.