Bug 125080 – When preserve-3d is disabled due to the GPU, it should not be reported as supported

• Status: NEW
• Component: CSS

[Gleb Smirnov]

Overview: 

  On *some* linux boxes running on *some* GPUs preserve-3d is broken in Webkit and browsers based on it (Google Chrome, etc). While the browser recognizes this value for (-webkit-)transform-style, it actually fails to render the corresponding page. Works fine in Mac OS and Windows.

  So, webkit should either reject preserve-3d or render it properly.



Steps to reproduce:

  1) Get your hands on a linux box with a not-so-modern GPU (e.g. Gallium 0.4 on AMD REDWOOD)
  2) Run this fiddle: http://jsfiddle.net/bZ5sE/3/



Actual results:

  Only the text "Looks like we have preserve-3d support - you should see red text below"  is displayed. No red text below is seen.



Expected results:

  a) The text "Looks like we have preserve-3d support - you should see red text below" should be displayed. Below it "should be seen only if preserve-3d is supported" should be seen in red
    
  b) The text "Sad times looks like there is no preserve-3d support - the red text below is probably hidden because of the preserve-3d styles applied." Should be displayed, with no red text following.


Build Date & Platform:
  
  First time encountered, but not investigated somewhere in April of 2013, in Chromium on Linux, GPU unknown.

Additional Builds and Platforms:

  All tested Linux distros and all tested Webkit-based browsers. Except on a laptop packed with Intel HD Graphics 4000, where everything ran smoothly in all tested browsers.

Additional information:
  Related github issues: https://github.com/Modernizr/Modernizr/issues/1116, https://github.com/jmpressjs/jmpress.js/issues/133#issuecomment-29117140

[Gleb Smirnov]

Actually, is also reproduced on some Windows machines, see this report: https://github.com/jmpressjs/jmpress.js/issues/133#issuecomment-29392417

[Simon Fraser (smfr)]

This means that whatever WebKit implementation you are running on these machines needs to turn off ChromeClient::ThreeDTransformTrigger on that hardware.