Bug 337700

Summary:	gwenview sometimes corrupts display by not fully updating the display of large images when scrolling up/down
Product:	[Applications] gwenview	Reporter:	Martin Walch <walch.martin>
Component:	general	Assignee:	Gwenview Bugs <gwenview-bugs-null>
Status:	RESOLVED FIXED
Severity:	normal	CC:	myriam, nate
Priority:	NOR
Version First Reported In:	Other (add details in bug description)
Target Milestone:	---
Platform:	Gentoo Packages
OS:	Linux
Latest Commit:		Version Fixed/Implemented In:
Sentry Crash Report:
Attachments:	screenshot showing the display corruption

Description Martin Walch 2014-07-22 13:57:34 UTC

Created attachment 87874 [details]
screenshot showing the display corruption

Sometimes when having a large image that is bigger in width and height than my screen, the display of the image gets corrupt when moving the image up or down.

It does happen always, but I have good chances to reproduce it with these steps:

1. open a large image (much bigger than the screen), e. g. the 1751x2356 Konqi image
> http://commons.wikimedia.org/wiki/File:Konqi-klogo-hi-res-1751x2356.jpg
which is bigger than my 1280x1024 screen. The file format is probably irrelevant as it happens with jpg files as well as with png files.
2. set zoom to 100%
3. move image up or down with the arrow keys or the mouse

The image should now show severe artifacts. If it does not happen, sometimes switching to fullscreen mode and then using the up/down keys triggers the bug.

The attachment is a screenshot that shows the problem with the Konqi image in fullscreen mode after arbitrarily moving the image with the mouse in all directions.

The gwenview version is from KDE Applications 4.13.3. Accordingly the gwenview version is probably 4.13.3, although it identifies itself as gwenview 4.13.1 (see bug #337698).

Comment 1 Martin Walch 2014-08-14 08:12:27 UTC

Looks like this was caused by one of the bugs in Qt 4.8 which have recently been fixed.

Comment 2 Martin Walch 2014-08-14 15:49:03 UTC

Well, or it is still there. Before closing this bug, I tried half an hour to reproduce the problem. Really looked like it was gone.

Now it happens again. I have no idea how this is triggered.

Comment 3 Nate Graham 2017-11-10 17:06:24 UTC

Can't reproduce using Qt 5.9.x and Gwenview from git master. Please leave a comment if you still see this with more recent software.