[cairo] CAIRO_STATUS_NO_MEMORY when passing incorrect scaling

[Paolo Bonzini]

Behdad Esfahbod wrote:
> Peter Clifton wrote:
>> Hi guys,
>>
>> I noticed, as I was debugging some drawing code, that after a certain
>> error in my code, all further cairo output was stopped.
>>
>> I tracked the problem down to an incorrect scale factor I was passing to
>> cairo_scale(), I was in fact passing the X scale factor as 0. due to a
>> corner case being hit at a certain zoom factor.
> 
> Yeah, that's a bug that we need to fix.  Scaling down to zero should not be an
> error.

If anything, my invalid-size-error branch should change this to an
invalid size error.  I agree that the error should be in the context...

Polo