Bug 25172

The game Coldest crashes when the water shader is being compiled, this is a regression from Mesa 7.6. Bisecting leads to this commit:

e4e312d493847e07ced026b93d2b588b8036ae02 is the first bad commit
commit e4e312d493847e07ced026b93d2b588b8036ae02
Author: Eric Anholt <eric@anholt.net>
Date:   Sat May 16 01:47:44 2009 -0700

    mesa: Add an optimization path to remove use of pointless MOVs.
    
    GLSL code such as:
    	vec4 result = {0, 1, 0, 0};
    	gl_FragColor = result;
    
    emits code like:
      0: MOV TEMP[0], CONST[0];
      1: MOV OUTPUT[1], TEMP[0];
    
    and this replaces it with:
      0: MOV TEMP[0], CONST[0];
      1: MOV OUTPUT[1], CONST[0];
    
    Even when the dead code eliminator fails to clean up a now-useless MOV
    instruction (since it doesn't do live/dead ranges), this should at reduce
    dependencies.

:040000 040000 f33f0fc67d7601a1605fbfeb702252208609ad04 a69c7263c3943f2ec9a074ae781d1bb68c0dd341 M	src

The shaders can be viewed here:
https://www.nemebean.com/svn/coldest/shaders/

System environment:
-- chipset: G45 / ICH10R
-- system architecture: 32-bit
-- Linux distribution: Debian unstable
-- Machine or mobo model: Asus P5Q-EM
-- Display connector: DVI
-- KMS: enabled
-- xf86-video-intel: 14109abf285866ad4cd99d0cd16b0954a0a73a62
-- xserver: 1.7.0
-- mesa: e8eec9385497053a4172deeff9c0ff2726a10f3b
-- drm: 83a35b68f45cebc70152e55ed3f99db485c9a7cd
-- kernel: 2.6.32-rc7 (debian)