Crash on rotation

[theozh]

When trying to rotate the red rectangle in order to let it snap to the horizontal guide, Inkscape crashes.

With Inkscape 0.92.1 r15371, Win10/64 it crashes reproduceably.
However, is seems to work with Inkscape 0.92.1 r15371, Win7/64.
Hence, a Windows10 problem?

That's the message I get under Win10/64:

terminate called after throwing an instance of 'Geom::LogicalError'
  what(): lib2geom exception: the passed coefficients give the empty set (E:\Temp\Inkscape\0.92.1\inkscape-0.92.1_64\src\2geom\line.cpp:66)

Emergency save activated!
Emergency save completed. Inkscape will close now.
If you can reproduce this crash, please file a bug at www.inkscape.org
with a detailed description of the steps leading to the crash, so we can fix it.

[TylerDurden (8thrule)]

Reproduced in Inkscape 0.92.1 r15371, Win 8.1 64bit

[jazzynico (jazzynico)]

Not reproduced on Windows XP (32-bit) Inkscape 0.92.1 and lp:inkscape/0.92.x rev. 15414.

[Hachmann (marenhachmann)]

Same as https://bugs.launchpad.net/inkscape/+bug/1765950 ?

[Spindizzy (spindizzy-wizard)]

Attached is a document that I have found reliably recreates the error. The error message is identical. The issue seems to be related specifically to rotation with snapping turned on. I created this document, and the instructions, by progressively cutting down an original document that had the issue. I then cut down on snapping settings until I found a minimal set that still trigger the error.

For me, it occurs in both of the following:

Inkscape 0.92.3 (2405546, 2018-03-11)

Inkscape 0.92+devel (1769e99ff8, 2018-12-01)

OS: Ubuntu 18.04.1

INSTRUCTIONS:

Select the three rounded rectangles. Select again to switch to rotation mode. Grab the lower right handle, and slowly rotate clockwise. Boom.

Interesting Points:

If you delete the blue circle, it doesn't happen.

If you turn off either "Snap to path intersections" or "Snap cusp nodes, incl. rectangle corners" it doesn't happen. You have to have both of those turned on.

Error Message:

terminate called after throwing an instance of 'Geom::LogicalError'
  what(): lib2geom exception: the passed coefficients give the empty set (/home/wilesed/workspace/inkscape/src/2geom/line.cpp:66)

Emergency save activated!

Additional Notes:

The error dialog appears to be what I'd call System Modal; you can't do anything else as long as it's up, and the close button appears to be inoperative. At the least, it takes a very, very, long time for it to finish up and close. Since this isn't an issue that could result in a system crash, could it be changed to an Application Modal dialog? That way I could get at my other windows while I'm waiting for Inkscape to finish whatever it's doing.

[Nathan Lee (nathan.lee)]

Hi - thanks for reporting this bug, I've manually migrated it to Inkscape's new
bug tracker on GitLab, and closed it here.

Please feel free to file new bugs about the issues you're seeing at
http://inkscape.org/report.

Moved to: https://gitlab.com/inkscape/inbox/issues/378
Closed by: https://gitlab.com/nathanal