[PATCH xserver 0/2] glx/dri2: Fix bug #50019.

[Michel Dänzer]

On Sam, 2012-07-28 at 10:28 -0700, Jeremy Huddleston Sequoia wrote: 
> On Jul 28, 2012, at 10:05, Julien Cristau <jcristau at debian.org> wrote:
> 
> > On Sat, Jul 28, 2012 at 09:58:46 -0700, Jeremy Huddleston Sequoia wrote:
> > 
> >> Ok, so then what do we do about this?  Is it really important enough
> >> to break ABI, even considering that 1.13 is just around the corner?
> >> I'd think not, but I'm willing to listen to arguments.
> >> 
> > I'm not sure why you say "breakage".  Adding an entry point isn't ABI
> > breakage.  I don't think anybody is going to mix 1.12.3's libdri2.so
> > with 1.12.4's libglx.so.
> 
> Right, sorry. That's ambiguous. By "ABI breakage", I'm referring in
> this case to the change in exported symbols (even just adding a newly
> exported symbol). I consider that breaking ABI, and you don't, but our
> disagreement over what constitutes "breaking" versus "changing" isn't
> really at issue. I'm just very cautious about API design, and I'd
> prefer to not get us into a jam if we can avoid it.
> 
> I agree that it's very unlikely that anyone would mix libglx.so and
> libdri2.so between versions, and yes of course making the symbol not
> exported would cause libglx.so to not be able to use it.

And you do realize the fix requires libglx.so to use it? :)


> The issue I'm concerned with is whether DRI2CreateDrawable2 will
> *only* be used by co-shipping code (ie code living in xserver like
> libglx.so) or if drivers (esp 3rd party binary-only drivers) might
> start using it directly.

According to Keith, there are no external users of DRI2CreateDrawable
after almost 4.5 years.


> That will get us into a situation where some servers advertising the
> same ABI version have DRI2CreateDrawable2 and some don't.

You could bump the ABI minor version.

Or you could use the fix I posted originally, which doesn't involve new
symbols (but comes with obvious risks).


Whatever you do, please don't leave 1.12 users prone to this annoying
bug.


-- 
Earthling Michel Dänzer           |                   http://www.amd.com
Libre software enthusiast         |          Debian, X and DRI developer