[cairo] Xlib/Xcb and EXTEND_PAD

[Thomas Jaeger]

I've done some more (very informal) testing, patching the intel driver
to disable acceleration for Reflect and Pad, and I couldn't (browsing in
firefox) tell a difference between acceleration and the server-side
fallback.  So having the fallback in the client really hurts more than
anything.

Zack Weinberg wrote:
> Thomas Jaeger <thjaeger at gmail.com> wrote:
> 
 >> How about this: disable cairo's fallbacks on X servers >= 1.5.99 and
> 
> I assume you mean >= 1.4.99?
> 
>> then fix the drivers when problems become apparent (where fixing can
>> mean resorting to the server's software fallback for now).
> 
> That might be okay for cairo in the abstract, but I'm not sure it works
> for Mozilla, how long is it going to take for up-to-date drivers to get
> into the hands of our userbase?

That's why I suggested 1.5.99 as the cut-off point.  xserver 1.5 is
already too widely deployed to be doing experiments like this, but I
think we have a chance to get the driver issues sorted out before the
next round of distributions.

Making this a hidden pref for mozilla will of course be fine as well,
although the distributions can also just patch this themselves.