cairo/BUGS

The place to find a current list of known bugs for cairo is:

	http://bugs.freedesktop.org

under either the cairo or libpixman products. New bugs should be
reported there as well.

[A few old bugs have not been moved to bugs.freedesktop.org and are
instead listed below:]

--

The caches need to be invalidated at font destruction time.

--

The polygon tessellation routine has problems. It appears that the
following paper has the right answers:

	http://cm.bell-labs.com/cm/cs/doc/93/2-27.ps.gz

	[Hobby93c] John D. Hobby, Practical Segment Intersection with
	Finite Precision Output, Computation Geometry Theory and
	Applications, 13(4), 1999.

Recent improvements to make the intersection code more robust (using
128-bit arithmetic where needed), have exposed some of the weakness in
the current tessellation implementation. So, for now, filling some
polygons will cause "leaking" until we implement Hobby's algorithm.

--

Stroke extents might not work for degenerate cases, (e.g. single
vertical or horizontal line).

--

Stroke width of 0 might do bad things.

--

Could there be a bug in PS backend exposed by?:

cairo_save
cairo_clip
cairo_restore
...

This needs a new testcase.

--

Text drawn with vertical metrics cannot currently use TrueType
subsetting for PDF/PS output as the code doesn't write out the necessary
VHEA or VMTX entries to the TrueType font objects. As a result, cairo uses
Type3 fonts which generates slightly different outlines.