[Piglit] New piglit/waffle with older X server

[Chad Versace]

On 02/20/2013 12:26 PM, Carl Worth wrote:
> I recently ran into a bunch of piglit tests not getting run, (returning
> "skip"), when they used to work fine. The tests say things like:
> 
> 	piglit: info: Failed to create GL 2.0 compatibility context
> 	piglit: info: Failed to create any GL context
> 
> I tracked the failure down via gdb to the following line of code in
> waffle (glx_config.c):
> 
>             if (attrs->context_full_version != 10 && !dpy->ARB_create_context) {
>                 wcore_errorf(WAFFLE_ERROR_UNSUPPORTED_ON_PLATFORM,
>                              "GLX_ARB_create_context is required in order to "
>                              "request a GL version not equal to the default "
>                              "value 1.0");
>                 return false;
>             }
> 
> In my case, attrs->context_full_version is 20.
> 
> When I asked about this in IRC, Eric helped me out a bit:
> 
> 	<anholt> cworth: your x server is old, and piglit/waffle don't
> 	fall back to just making an old context and seeing if it's good
> 	enough.
> 
> I'll go ahead and upgrade my X server so I can get things running again,
> but I'm left with the following questions:
> 
>   1. I'm curious what's the new thing required in the X server here?
> 
>      I'm obviously running tests that worked previously, so I'm not
>      really needing any new behavior. So this looks like a regression in
>      piglit/waffle.

This is definitely a piglit, not waffle regression. I suspect commit 3a92ffa0e.

>   2. Assuming this is a bug, should the missing fallback code be added
>      to piglit or to waffle?

Paul suggested a reasonable fallback path. The fallback requires calling
glXMakeCurrent and glGetString, which shouldn't be done by waffle.

> 
>   3. If waffle, Chad do you have a bug tracker set up for waffle? If
>      not, shall we add a component to bugs.freedesktop.org?

There's no bugtracker, but I wish there was.

> 
>   4. If we don't add automatic fallback code, is there some logical
>      place that we could put a better error message in place? It was not
>      at all obvious to me from "failed to create context" that my X
>      server had suddenly gotten too old, (when it worked previously).

Waffle reports good error messages, but Piglit doesn't. I'll look into updating
Piglit to report Waffle error messages in full.