[cairo] Access violation in _cairo_surface_acquire_dest_image

[Chris Wilson]

Jacob (=Jouk) Jansen (joukj at hrem.nano.tudelft.nl) said: 
> When trying to run the cairo tests&libs, extracted from the git-repositry
> recently I get on my OpenVMS machine
> 
> %SYSTEM-F-ACCVIO, access violation, reason mask=00, virtual address=000000000000
> 001C, PC=000000000012A970, PS=0000001B
> %TRACE-F-TRACEBACK, symbolic stack dump follows
>   image    module    routine             line      rel PC           abs PC
>  libcairo  cairo-surface  _cairo_surface_acquire_dest_image
>                                         24365 0000000000001370 000000000012A970

Hmm, this implies that surface->backend is NULL within
_cairo_surface_acquire_dest_image - 0x1c is the offset of
backend->acquire_dest_image. (I was thinking this was the patch
I made to remove the cairo_image_surface_backend from the error
surfaces, which reduces cairo's .data down to below 1 page, but it seems
I've yet to push that one...) 

However, as this is impossible (!), a little more detective work is in
order. Could you try to git bisect the broken commit? Thanks.
--
Chris Wilson