Bug 74158

Summary: Option "BackingStore" is not honored
Product: xorg Reporter: Aaron Plattner <aplattner>
Component: Server/DDX/XorgAssignee: Adam Jackson <ajax>
Status: RESOLVED MOVED QA Contact: Xorg Project Team <xorg-team>
Severity: normal    
Priority: medium CC: brebs, facorread, headcrabextra, kokoko3k, s_chriscollins
Version: unspecified   
Hardware: Other   
OS: All   
Whiteboard:
i915 platform: i915 features:

Description Aaron Plattner 2014-01-28 19:55:19 UTC 
Sufficiently recent X servers enable backing store when the Composite extension is enabled, and use Composite to implement WhenMapped support.  This causes problems with SDL 1.2 games because they request backing storage whenever the server says it supports it:

http://hg.libsdl.org/SDL/file/22a7f096bb9d/src/video/x11/SDL_x11video.c#l1096

According to the code, you're supposed to be able to disable backing store by setting

  Option "BackingStore" "off"

in the "Screen" section of xorg.conf.  Indeed, xf86SetBackingStore implements this just fine.  However, the Composite extension comes along later and overrides the backing store support based on the value of the global 'disableBackingStore' flag.  This flag is set in ProcessCommandLine if the -bs flag is passed to the server, but not by xf86SetBackingStore.
Comment 1 GitLab Migration User 2018-12-13 18:29:15 UTC 
-- GitLab Migration Automatic Message --

This bug has been migrated to freedesktop.org's GitLab instance and has been closed from further activity.

You can subscribe and participate further through the new bug through this link to our GitLab instance: https://gitlab.freedesktop.org/xorg/xserver/issues/164.

Use of freedesktop.org services, including Bugzilla, is subject to our Code of Conduct. How we collect and use information is described in our Privacy Policy.