[Bug] Getting opengl function address panics if the address contains a null terminator

[morr0ne]

Window.get_proc_address accepts a &str which gets then converted to a CString without checking for null bytes and just calling unwrap. Passing a &str with internal null bytes will crash the program. The conversion can also be expensive considering that most opengl loaders will use a CString/CStr directly. This means that in most cases the following conversion happens:
CString => &str => CString.

it's probably a good idea for get_proc_address to ask directly for a &CStr and let the library user handle the conversion if necessary.

related #1314

[kchibisov]

That makes sense, could probably change that.

[morr0ne]

Upon further inspection it looks like some tools like the one used in the examples (gl_generator) use &str for loading, hence probably why that was used. Making a change like that probably also means changing the generator used. Phosporus seems to be the best alternative, it used by glow and transitively by bigger projects like wgpu and bevy.

[kchibisov]

Fixed in #1435.