Regression between 23.0.4 and 23.1.0: texture glitches in osgEarth
I'm tracking down a bug/regression that recently appeared when RedHat updated their Mesa packages. I have confirmed that the issue was introduced and exists in ANY Mesa tag newer than 23.0.4; that is, 23.1.0 -> 23.3.3. I have attached a trace file that SHOULD demonstrate the bug on any Mesa newer than 23.0.4. In the "working" scenario you'd see a simple earth model, nothing spectacular. However, in the "bug" scenario, there will be very obvious blue/white discoloration.
I've done some of my own testing inside a Mesa 23.1.0 tag locally, making changes and building/installing into ~/local (and setting LD_LIBRARY_PATH to ensure the "testing" build is found first). However, nothing I've tried so far has helped.
What I SUSPECT is the offending line in the shader is, essentially, when it copies a value out of gl_MultiTexCoord0 to be used elsewhere, though I could be wrong. I'll continue to do my own testing in the interim, but any advice would be greatly appreciated.
Trace attached; should show obvious glitches/weirdness in Mesa 23.1.0 or higher. Thanks