Bug in interaction between freeglut and mesa-7.3-rc2

[Ian Romanick]

On Sat, 2009-01-17 at 11:28 +0100, Florian Echtler wrote:
> >> The bug causes a segfault in libGL.so, though even with debug info
> >> enabled, I can't see the exact location. However, I can work around the
> >> bug when, in freeglut, I replace
> > Why would you do that?  There is no improvement to freeglut and no
> > benefit to its users.  If the read drawable and the drawing drawable are
> > always the same, just use glXMakeCurrent.  You already have a tool that
> > does *exactly* the job you need done.  Why change to a tool that is
> > intended to suit a different need?
> Uh, I do that because I need to use freeglut with the opensource drivers 
> and DRI? It won't work otherwise. Note: freeglut currently contains 
> _glxMakeContextCurrent_, which I replaced by _glXMakeCurrent_, not the 
> other way round.

Apologies.  I misread the original message.  For whatever reason (blame
it on being Friday), I thought you were replacing glXMakeCurrent with
glXMakeContextCurrent, not the other way around.

> If I remember correctly, I already posted this patch to the freeglut 
> mailing list last fall, where it was rejected, citing possible side 
> effects on other platforms. As I am not a regular freeglut developer, I 
> accepted that and (wrongly) concluded that it has to be fixed in Mesa.
> 
> So let me summarize:
> - there is a bug in Mesa which causes glxMakeContextCurrent to segfault,
> - but it only occurs because freeglut doesn't call glXMakeCurrent, as it
>    really should, and passes invalid parameters, too.

There are two bugs in freeglut:

- It calls a GLX 1.3 function on a system that doesn't support GLX 1.3.
- It passes the wrong kind of drawable ID to glXMakeContextCurrent.

> If that is correct, could somebody with more authority than me 
> please convince the freeglut guys to fix it? As freeglut is the default GLUT 
> implementation on most distros, I consider this quite important for 
> acceptance of the opensource DRI drivers.. a _lot_ of software uses GLUT, 
> and consequently crashes.

Do they have a bugzilla?  Is there an open bug for this issue there?

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