http://bugs.winehq.org/show_bug.cgi?id=19396
--- Comment #6 from Dylan Smith dylan.ah.smith@gmail.com 2009-07-30 08:23:45 --- (In reply to comment #5)
There is one subtle element I missed. Prior to the patch that caused the regression, if the vertical scroll thumb was placed away from the bottom of its range, each arrival of new text would cause it to be forced down to the bottom, thus the text that had just been rendered would be visible in the viewport. Whereas now, the thumb is not forced down whenever new text arrives, so the new text is rendered below and thus outside of the viewport.
Just because it behaves differently doesn't mean it is a bug. I tested on Windows XP with the application, scrolled up using the scroll thumb, then pressed enter to append a new line to the text, and it didn't scroll down (neither did waiting for a message to appear). This is what wine now does, so it isn't a regression, it is a bug fix.
Let me know if I am not understanding the steps to reproduce this regression that you reopened this bug for. Otherwise please test against Windows or native richedit before reporting a non-obvious bug.