[Dri-devel] bug in dri_mesa.c

[Bill W. <bil...@gr...>]

This is a problem on the tdfx-2-1-branch.  I suspect it is a problem
on all the branches, and with all the drivers.

In the function driMesaDestroyContext, around line 653 there are
these lines:

	(*pcp->driScreenPriv->MesaAPI.DestroyContext)(pcp);
        gl_destroy_context(pcp->mesaContext);

The DestroyContext member in the tdfx driver, and all of the drivers
as far as I can see from looking at the code, deallocate all of the
private data in the driver associated with the context.  Unfortunately,
the tdfx driver needs this data inside of gl_destroy_context.  The
chain of calls
  gl_destroy_context
    gl_free_context_data
      free_shared_state
        *ctx->Driver.DeleteTexture
needs the private driver data.  If you play UT, you get a segfault
leaving the game caused by this.

I believe everything works out alright if you swap the two statements,
destroying the mesaContext first, and then destroying the pcp.

I have tested this fix with the tdfx driver, and I am going to check
it into the branch I work on.  But other branches will have the same
problem.

-- 
There's no art to find the Mind's Construction in the ASCII
Hamlet, Act 1, Scene 1 (first draft)
Bill White <bil...@gr...>           Griggs Research Institute