846963 - Text distortion on pages when scrolling

Status: RESOLVED DUPLICATE of bug 812695

(Firefox :: Untriaged, defect)

Description

[Cooee]

Attachment: textbug2.png

User Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:19.0) Gecko/20100101 Firefox/19.0
Build ID: 20130215130331

Steps to reproduce:

I made no changes to Firefox. I think this may have started occuring once Windows update KB2670838 was installed, however I have since uninstalled it and the problem persists. I have been using Firefox for years on this machine, and this only just started happening.

I tried disabling all addons and plugins and restarting Firefox but it didn't fix the problem. I have not yet tried reinstalling Firefox.

I just noticed that this problem also happens on the text entry field I am using to submit this report when I click and hold the scroll bar. As soon as I release the mouse button, the distortion goes away (the on mouse release event must cause a repaint?).


Actual results:

Text randomly becomes distorted when scrolling around web pages. It happens regardless of using the scroll wheel or moving the scroll bar around.

Scrolling away from and back to the area will sometimes fix the problem (it will render / paint correctly upon returning). Selecting and de-selecting the text will always fix it.

The problem does not occus on page load, only after scrolling.

Note the distortion in lines 7 - 13 (410251 - 413669) on the attached screenshot.


Expected results:

The text distortion should not have occurred.

Comment 1

[Cooee]

Attachment: Second example of the problem

Another instance of this. Note the top two news stories exhibit the problem, however the fixed div / sidebar isn't affected in the equivilant section, because it doesn't scroll off the screen.

Comment 2

[Loic]

Workaround: Disable HWA in Firefox (https://support.mozilla.org/en-US/kb/forum-response-disable-hardware-acceleration) or remove Win 7 update KB2670838.