Reading RGBA color via glReadPixels from an RGB visual should always give an alpha value of 1.0. However, on RGB8 visuals that are stored in R8G8B8x8, the alpha value is coming back as random values. This started with anholt's recent changes to intel fbconfigs.
I have listed this against i965, but I suspect that it impacts other Intel chipset drivers as well.
increasing priority as this seems to be impacting many cases.
mustpass.c seems happy now -- do you have a specific testcase?
Author: Eric Anholt <email@example.com>
Date: Wed Feb 25 22:54:51 2009 -0800
intel: Fix up x8r8g8b8 renderbuffer format so that alpha=1 spans code happens.
I was lured into a false sense of security by the fact that the spans code was
already there, and a bunch of tests didn't catch the problem. oglconform's
mask.c did, though.
*** Bug 19543 has been marked as a duplicate of this bug. ***
*** Bug 20321 has been marked as a duplicate of this bug. ***
Mass version move, cvs -> git