Created attachment 627772 [details] [diff] [review] patch Per WebGL spec section 5.14.14. Test: https://cvs.khronos.org/svn/repos/registry/trunk/public/webgl/sdk/tests/conformance/extensions/get-extension.html
Unicode case-insensitive or ASCII case-sensitive? In particular, should you be able to use 'LATIN CAPITAL LETTER I WITH DOT ABOVE' (U+0130) instead of i? Sounds like something you should have a test for... ;)
The spec fails to specify it, but obviously the intent is that extension strings can only use [a-zA-Z0-9_] characters. Will write to the list about that. Yes, a test checking that non-ASCII strings are rejected with INVALID_VALUE could make sense.