After an evaluation, GNOME has moved from Bugzilla to GitLab. Learn more about GitLab.
No new issues can be reported in GNOME Bugzilla anymore.
To report an issue in a GNOME project, go to GNOME GitLab.
Do not go to GNOME Gitlab for: Bluefish, Doxygen, GnuCash, GStreamer, java-gnome, LDTP, NetworkManager, Tomboy.
Bug 637635 - set_bounds() on goocanvas.Canvas with large width
set_bounds() on goocanvas.Canvas with large width
Status: RESOLVED NOTABUG
Product: goocanvas
Classification: Other
Component: general
0.15
Other Linux
: Normal critical
: ---
Assigned To: goocanvas-maint
goocanvas-maint
Depends on:
Blocks:
 
 
Reported: 2010-12-20 06:51 UTC by Jonathan
Modified: 2011-09-24 14:05 UTC
See Also:
GNOME target: ---
GNOME version: ---


Description Jonathan 2010-12-20 06:51:44 UTC 
I have found an issue when setting the bounds of a goocanvas.Canvas object larger than 32,606 pixels wide.  It's a difficult bug to reproduce, but it only seems to happen on Ubuntu 10.10, and not the previous version of Ubuntu (10.04).  Both of those OSes use libgoocanvas 0.15, so I'm not sure why the behavior would be different.

OpenShot Video Editor uses goocanvas to render it's timeline.  When the timeline exceeds 32,606 pixels in width, it starts to behave very strange.  For example, as you move other goocanvas items around, they disappear, and all goocanvas groups seem to ungroup.  As I said, very strange behavior.  

Any thoughts on how to proceed with a bug like this?

Thanks!
-Jonathan
Comment 1 Damon Chaplin 2010-12-20 11:00:16 UTC 
You might be hitting the cairo coordinate limits. It used to use 16.16 fixed point coordinates, so you were limited to +-32768. Since 1.6 it uses 24.8 so the limit is larger. (The "Coordinate Spaces and Limits" page of the docs mention this.)

What versions of cairo are you linking to?
Comment 2 Maël Lavault 2010-12-20 12:09:50 UTC 
I have the same bug, i'm using cairo 1.10, goocanvas 0.15 and pygoocanvas 0.14.1.
Comment 3 Damon Chaplin 2010-12-20 12:57:45 UTC 
Actually this might be due to a pixman bug, see bug 625299.

Make sure you have pixman 0.19.4 or above.
Comment 4 Maël Lavault 2010-12-20 13:21:39 UTC 
I have pixman 0.20 ;)
Comment 5 Damon Chaplin 2010-12-22 22:01:19 UTC 
If someone can create a simple test app to reproduce the bug that would be useful.
Comment 6 Jonathan 2011-01-02 06:27:52 UTC 
It looks like this is in fact related to the cairo coordinate limits.  I have found many different reports (just googling around) which seem to confirm this behavior.  So, for the time being, I am going to fix OpenShot to not exceed the 32,000 limit.  Thanks.
Comment 7 Damon Chaplin 2011-09-24 14:05:05 UTC 
I'll mark this as NOTABUG then. Reopen if it happens again.