On Sat, 11 Oct 2014, Stefan Behnel wrote:
Yaroslav Halchenko schrieb am 11.10.2014 um 16:18:
On Wed, 10 Sep 2014, Stefan Behnel wrote:
on behalf of the Cython dev team, I'm pleased to announce the release of Cython 0.21, a major feature release. Thanks everyone who contributed code, documentation improvements, test feedback, bug reports and/or otherwise helpful insights for this release.
a little change detected while down-stream testing builds in Debian (previous version was 0.20.2 and it built fine)
------------------------------------------------------------ ... vertex_format.last_shader = self for i in xrange(vertex_format.vattr_count): attr = &vertex_format.vattr[i] if attr.per_vertex == 0: continue attr.index = glGetAttribLocation(self.program, <char *><bytes>attr.name) ^ ------------------------------------------------------------
kivy/graphics/shader.pyx:448:63: Casting temporary Python object to non-numeric non-Python type
Wow, interesting piece of code. What's that even supposed to do?
Looking up their code, I find that "attr.name" is a char*:
https://github.com/kivy/kivy/blob/master/kivy/graphics/vertex.pxd
So the above code creates a temporary Python bytes object by copying data from a char*, then gets the char* to the internal object buffer and throws the object away, thus deleting its buffer. Then it passes that invalidated char* into a function. I can't see how this makes any sense. And I'm happy to see that Cython catches this kind of bug now.
I wondered if that is an intentional restriction now to restrict such casting only to numeric (and exclude the simplest form -- bytes/chars) or a regression?
It seems they fixed their code already:
https://github.com/kivy/kivy/commit/827bd6c7b7d04ec72cb3bdbf0ffcd90630d90008
Gotcha -- THANKS a bunch for a detailed response! CCing kivy maintainers in Debian -- get ready for upcoming cython 0.21 upload - a little patch to pick up! ;) -- Yaroslav O. Halchenko, Ph.D. http://neuro.debian.net http://www.pymvpa.org http://www.fail2ban.org Research Scientist, Psychological and Brain Sciences Dept. Dartmouth College, 419 Moore Hall, Hinman Box 6207, Hanover, NH 03755 Phone: +1 (603) 646-9834 Fax: +1 (603) 646-1419 WWW: http://www.linkedin.com/in/yarik