So.. you may or may not know PCSX2, the ps2 emulator.
While developing it, I kind of hit a snag with AMD and just AMD OpenGL driver.
Aside of performance issues (half of direct3D, while other vendors are 100% on par), I get garbled graphics every time I enable this extension.
At first I thought it could be a problem with my code, but after writing a testcase (attached) it must definitively be something within driver.
Please, notice how you get a yellow frame. If you test this on an intel, nvidia or even amd card with open source drivers under linux, it's green.
It seems second index color of shader isn't properly outputed.
Perhaps it's optimized away in a separate program? If I try a monolithic build everything looks just fine.
I can confirm this happens with every driver (15.12 too) on both Windows 7 and 10, and a HD5770 and HD7750.
And this somewhat suggests me it's a problem affecting *every* card and OS.
EDIT: attached right source file