Contoured circle reshaping crash

[WKraven]

Attempts to reshape (or to move by altering coordinates) the contoured circle in the attached file reliably results in a crash.

Inkscape 0.91 r13725
Parabola GNU/Linux i686

[Liam P. White (liampwhite)]

Confirmed on Ubuntu 14.04.2 LTS with Inkscape 0.91+devel r13964

[Liam P. White (liampwhite)]

Attaching backtrace on Ubuntu 14.04.2 with Inkscape 0.91+devel r13964.

[jazzynico (jazzynico)]

Reproduced on Crunchbang Waldorf, Inkscape trunk rev. 13966, but only when the "Scale stroke width" option is on.

No crash with 0.48.3.1. Instead, any attempt to resize the object adds a transform [matrix(0,0,0,0,0,0)] that makes it disappear.

[Alvin Penner (apenner)]

on Windows 7, Inkscape 0.91, I get the crash message:

C:\Program Files\Inkscape>inkscape

** (inkscape.exe:3004): WARNING **: SPObject::updateDisplay(SPCtx *ctx, unsigned int flags) : throw in ((SPObjectClass *) G_OBJECT_GET_CLASS(this))->update(this, ctx, flags);
terminate called after throwing an instance of 'Geom::ContinuityError'
  what(): lib2geom exception: Non-contiguous path (src/2geom/path.cpp:91)

Emergency save activated!

[su_v (suv-lp)]

Findings as discussed with Liam P. White on irc (#inkscape-devel):

21:52 FailBit : probably still happens before this, but maybe: https://bazaar.launchpad.net/~inkscape.dev/inkscape/trunk/revision/12990
21:55 su_v : crashes with r12988 too
21:57 su_v : with r10795, no crash, but the resized object gets this transform:
21:57 su_v : matrix(0,0,0,0,0,0)
21:57 FailBit : the zero matrix
21:57 su_v : position, and size is zero (SVG origin)
21:57 FailBit : is not invertible
21:57 FailBit : has a lot of bad qualities
22:02 su_v : 12503 -> zero matrix, 12600 doesn't crash and scaling works
22:02 su_v : 12700 -> crash
22:03 su_v : 12650 -> no crash, scales as expected
22:07 su_v : 12676 -> no crash, scales (but stroke width seems different - doesn't show fill area anymore, unlike earlier builds)
22:07 su_v : 12678 -> crash
22:08 su_v : http://bazaar.launchpad.net/~inkscape.dev/inkscape/trunk/changes/12678
22:08 FailBit : 12677
22:08 FailBit : it wouldn't be 12678 I don't think
22:10 su_v : confirmed with different archived build (12676: no crash, 12677: crash)

[Alvin Penner (apenner)]

yes, the error is coming from the routine get_scale_transform_for_variable_stroke() in sp-item-transform.cpp, which I have modified in the past, I'll look into it...

[Alvin Penner (apenner)]

fix committed to rev 13970

[ScislaC (scislac)]

trunk r13970 backported in 0.91.x r13758