Created attachment 41234 [details]
Screenshot showing the problem
Run the test application from bug 30393.
Scroll to the bottom, then move the scrollbar back to the top slowly.
The svg that was included with img src= now has white lines all over it (probably an off-by-1 in repainting it, leaving 1 line from the frame).
This problem does not occur when using -graphicssystem raster
Looks like a bug in Qt's X11 paintengine to me, although my attempt at hacking together a reduced testcase was unsuccessful.
Please follow the QtWebKit bug reporting guidelines when reporting bugs.
- The 'QtWebKit' component should be used for bugs/features in the public QtWebKit API layer, not to signify that the bug is specific to the Qt port of WebKit
Changed component to SVG, so it shows up in my all-svg-bugs search.
Created attachment 74383 [details]
Test case from 30393
X11 paintengine bugs are not relevant anymore since Qt is switching to raster by default in 4.8.