Crash using CTRL constraint

[LucaDC]

I use Inkscape for technical drawings so guides, snap everywhere (25) and CTRL drag.
When there are a lot of snapping possibilities around, if I drag with CTRL to move an object orthogonally the program usually crashes and, before closing, informs me that the backup of current drawing failed (but not always; I couldn't say for what reason). Sometimes, when I'm lucky, I press ESC to close the "crash notification" window and can keep working so I can save and restart (but I've also tried, after saving, going on without experimenting bad things...); more often Inkscape closes and everything is lost.
Now I never use CTRL without saving first! Or I have to place a guide but it's annoying because after I also have to remove it. CTRL is much more easy and immediate.

Inkscape v0.46, Windows XP SP3, 2 GB RAM (paging deactivated), usually maximized window while working.
Guides active and snapping, no grids, snap to nodes, objects, tracks, only if nearer than 25 (all three).
Tell me if I can do something to give more information about these crashes (dump, error logs, etc...).

[Alvin Penner (apenner)]

In Windows you can sometimes trap useful exit messages on a crash by running Inkscape from a DOS prompt and implementing one of the techniques outlined in :
http://kaioa.com/node/42 or http://kaioa.com/node/63

hth
Alvin

[Alvin Penner (apenner)]

- similar to Bug 274423 ?
- could you attach a drawing for experimentation purposes ?

[LucaDC (lucadc)]

Perhaps the cause of Bug 274423 is the same. Anyway I followed the procedure but could not easily cause a crash.
I really couldn't say under which conditions this happens, if trying to snap to 2 objects at a time or when there are a lot of near possibilities.
In any case it seems nondeterministic: I've saved a document, immediately after caused a crash, restarted Inkscape, loaded the document redone the same thing (I suppose, it's not easy to redo it in the exact same way) and nothing happened.

I also used "Inkscapec", as suggested, to extract console messages but apart for some complaints when opening PDFs, nothing was reported when crashing.

As soon as I found a situation easily reproducible, I'll attach the drawing and the procedure.

[Diederik van Lierop (mail-diedenrezi)]

Could you please test a recent development version? These will be more unstable, but this specific snapping bug might have been solved already. If not then please tell me, so I can try fixing this before the next release. Snapping has improved significantly after our latest v0.46 release.

Thanks for reporting.

[LucaDC (lucadc)]

Found the same problem in Inkscape 0.46+devel, revision 20046, built Oct 24 2008. Still I can't find a way to reproduce it regularly. Anyway, now it seems to hang more when just snapping than only while CTRL-dragging.
No significant output from Inkscapec, as before.
I also tried using gdb to make a dump but I can't open saved files when under it: it seems to hang (I killed the process after 2-3 minutes having CPU at maximum). Is there a way to "turn debugging on" after a while? I'll take a look at gdb manual...

Sorry for giving so little information about this issue.
By the way, I can confirm that snapping is much better now.

[Diederik van Lierop (mail-diedenrezi)]

Hi Luca,

To open a file when running Inkscape in gdb, you should use "run c:\temp\your-file-name.svg", instead of just "run".

If you could get a useful backtrace than that would be really great!

[Diederik van Lierop (mail-diedenrezi)]

If this really is a duplicate of bug 292077, then it might have been fixed as of rev. 20205

[LucaDC (lucadc)]

Solved with SVN 20205.
Thanks again, Diederik.