Bug 3683 - R_FindShader(): negative lightmap indexes cause stray pointers
Status: RESOLVED FIXED
Alias: None
Product: ioquake3
Classification: Unclassified
Component: Misc
Version: GIT MASTER
Hardware: All All
: P3 minor
Assignee: Zachary J. Slater
QA Contact: ioquake3 bugzilla mailing list
URL:
Depends on:
Blocks:
 
Reported: 2008-06-13 06:30 EDT by Ben Noordhuis
Modified: 2008-07-05 19:51:53 EDT
0 users

See Also:

Attachments
Catch negative lightmap indexes and default to LIGHTMAP_BY_VERTEX (1.45 KB, patch)
2008-06-13 06:32 EDT, Ben Noordhuis

Description Ben Noordhuis 2008-06-13 06:30:08 EDT 
And you end up with a surreal image on your screen or, more likely, a segfault.

Negative indexes are allowed (-1 to -4 are reserved for built-in lightmaps) but R_FindShader() fails to check for indexes < -4. When later on said index is used to index an array, Unpredictable Behaviour emerges. Though, perhaps, not really unpredictable.
Comment 1 Ben Noordhuis 2008-06-13 06:32:33 EDT 
Created attachment 1784 [details]
Catch negative lightmap indexes and default to LIGHTMAP_BY_VERTEX

Added a warning in code/renderer/tr_local.h that changes to the LIGHTMAP_* defines must be reflected in R_FindShader().
Comment 2 Tim Angus 2008-07-05 19:51:53 EDT 
Fixed in r1405.