Bug 83314

Summary: Wrong XcmsTekHVCFormat to XcmsRGBFromat color conversion on 32 bit systems
Product: xorg Reporter: Dimitri Sokolyuk <demon>
Component: Lib/XlibAssignee: Xorg Project Team <xorg-team>
Status: RESOLVED MOVED QA Contact: Xorg Project Team <xorg-team>
Severity: normal    
Priority: medium    
Version: unspecified   
Hardware: x86 (IA32)   
OS: All   
Whiteboard:
i915 platform: i915 features:
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Description Flags
Test application and results for 32 and 64 bit systems none

Description Dimitri Sokolyuk 2014-08-31 20:48:09 UTC 
Created attachment 105512 [details]
Test application and results for 32 and 64 bit systems

Conversion from XcmsTekHVCFormat into XcmsRGBFromat gives on 32 bit systems wrong results for upper half of Hue values (over ca. 148.0). Results in lover half are tinted too. 64 bit systems are not affected.

Simple test application is included along with results for 32 bit system (wrong results) and for 64 bit system (expected results).

Tested on 32/64bit OpenBSD 5.5/5.6, OS X 10.9 (XQuartz) and various 32/64bit Linux systems. Bug appears at least (but is not limited to) on Xorg versions 1.14.5 to 1.15.2.

See also discussion on bug hunting: https://www.linux.org.ru/forum/development/10810167 (russian)
Comment 1 Dimitri Sokolyuk 2014-08-31 21:59:21 UTC 
UPD: as far as I could go back in time, the bug exists on additionally tested Xorg 1.8.2 (OpenBSD/i386 4.8) and Xorg 7.2.0 (OpenBSD/i386 4.2) too. And may be ever prior.
Comment 2 Dimitri Sokolyuk 2014-09-01 10:52:18 UTC 
may be related: https://bugs.freedesktop.org/show_bug.cgi?id=9949
Comment 3 GitLab Migration User 2018-08-10 20:10:49 UTC 
-- GitLab Migration Automatic Message --

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

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