[cairo] cairo_save trashes global variable

[Andy Hopper]

Running into a really strange issue with cairo_1.16 on Centos7 wherein
calling cairo_save() causes a completely unrelated global variable to be
modified. I don't see anything in the documentation would explain this.
I actually ran into this with cairo-1.15 which is stock in CentOS, ran
into this and built 1.16 locally and am running into the same thing.
Curious if anybody has ever run into anything like this?

Thanks!

Andy