[PATCH xserver] randr: Stop dirty tracking for shared pixmap being destroyed

[Alex Goins]

On Tue, 8 Dec 2015, Alex Goins wrote:

> > > Are you sure about this? rrCreateSharedPixmap() does not actually start pixmap
> > > tracking, rather it is done later in rrSetupPixmapSharing(). It's not a given
> > > that a 'shared pixmap' is being tracked when it is destroyed.
> > 
> > That's fine, StopPixmapTracking is just a no-op in that case.
> 
> Sure, if you want to depend on edge cases in an external driver. Seems to me
> like it would be best to do the right thing inside the modesetting driver
> instead of making unnecessary assumptions about the source driver's behavior.

Err, inside randr, not the modesetting driver. Nonetheless.

Thanks,
Alex