Bug 340971

Summary: Compositing type is overridden when not supported
Product: [Plasma] kwin Reporter: Michael Mounteney <kdebugs>
Component: generalAssignee: KWin default assignee <kwin-bugs-null>
Status: RESOLVED INTENTIONAL    
Severity: normal    
Priority: NOR    
Version: unspecified   
Target Milestone: ---   
Platform: Gentoo Packages   
OS: Linux   
Latest Commit: Version Fixed In:
Sentry Crash Report:

Description Michael Mounteney 2014-11-14 22:12:44 UTC 
If one logs in via hardware that supports OpenGL compositing, it is possible to set the System Settings / Desktop Effects / Advanced / Compositing Type to OpenGL and enjoy the benefits thereof.  However, if one then logs out and logs in again via different hardware (e.g., xdmcp remote) that does not support OpenGL, the compositing type is reset to XRender so that if one then returns to the first hardware, the setting of OpenGL is lost.

Solution:  don't have KDE overriding values that the user has specified.  If it is considered desirable, warn via a dialog, but provide the option not to override.  I.e., the dialog should ask "This setup doesn't support OpenGL;  do you want to fall back to XRender ? Y/N" with the tick-box "don't ask this question again".
Comment 1 Martin Flöser 2014-11-15 08:27:06 UTC 
I'm sorry to say, but this is an intended behavior. The thought is that you don't end up on an unusable system because it uses unsupported OpenGL. We tried to get the best possible solution and switch to XRender once we notice OpenGL is broken. That way further startups don't even try to setup OpenGL just to notice that it breaks.