http://bugs.winehq.org/show_bug.cgi?id=19396
--- Comment #1 from Dylan Smith dylan.ah.smith@gmail.com 2009-07-20 23:20:09 --- Created an attachment (id=22492) --> (http://bugs.winehq.org/attachment.cgi?id=22492) Let WM_VSCROLL message be sent to scroll richedit control
The WM_VSCROLL message is documented as a notification sent when a scrolling event occurs, however, the application was using this to scroll the text in the richedit control. Apparently this works.
Previously this bug was not visible since ES_AUTOVSCROLL was always simulated without checking for the style flag. The application removes this style by using EM_SETOPTIONS, so the automatic scrolling wasn't being performed anymore after my recent patch.
The attached patch will fix the issue, but it isn't done right, so I am not submitting it.
First of all WM_HSCROLL and EM_SCROLL probably have the same behaviour, but this still needs to be tested to confirm.
Second of all WM_VSCROLL specifies the scroll position as a 16-bit value, so overflow needs to be avoided for large amounts of text. I did some testing, and it seems as if nMax for the scrollbar is capped at 0xFFFF for native richedit controls after a large amount of text has been loaded. Normally nMax corresponds to the height of the text in pixels, so I guess this is scaled after the text gets to large.