Created attachment 68176 [details]
pattern bug example
There is a bug by creating a line with
cairo_pattern_create_linear() and cairo_pattern_add_color_stop_rgba().
If the offset of cairo_pattern_add_color_stop_rgba() in the first call is 0.0 and in the other 1.0 it works fine with Adobe Acrobat Reader and Evince document viewer on ubuntu 12.04.
If I set the offset to 0.5 on both function calls in Adobe Acrobat Reader and in Evince document viewer the line disappears also on Ubuntu 12.04.
I also attached the example as source code and views from document viewers.
This bug has no effect on png outputs.
Created attachment 68177 [details]
working example of pattern
Created attachment 68178 [details]
Created attachment 68179 [details]
bugged view adobe
Created attachment 68180 [details]
bug view evince
Can't reproduce with git/master, bug was already fixed.
Git bisect finds (which is commit 1.10.0-231-g3cbe82f aka 1.11.2~98, so anything 1.11.2 or newer should be fine):
Author: Andrea Canciani <firstname.lastname@example.org>
Date: Sun Dec 12 22:29:56 2010 +0000
ps,pdf: Deal with empty domain gradients.
If all the stops of the gradient have the same offset and the
pattern's extend mode is EXTEND_PAD, then we cannot use the stops'
domain as the interpolation parameter range because this would produce
a gradient with the same start and end objects. Such ranges tickle
bad behaviour in rasterisers.
We replace the color function with an appropriate step function
defined on [0 1].
Fixes radial-gradient-one-stop for pdf and ps3.
Reviewed-by: M Joonas Pihlaja <email@example.com>