Crashes on shift/ctrl+click on control handles of shapes (e.g. rectangle rounding, ellipse to circle, make circle whole, ...)

[PittMonkeyAT]

Inkscape: ver. 0.91
OS: Windows 10 Home, x64, ver. 1511, Build 10586.420

Open new document. Draw rectangle. Drag to adjust vertical rounding radius. Shift+click to remove vertical rounding radius. App shuts down. Sometimes it takes two or three clicks but it always happens.

Attached a video. App crashes at the moment the video ends b/c Windows native video recorder stops when the current app stops.

[PittMonkeyAT (ncerniglia)]

Also affects making ellipse whole (closing ellipse after creating segment).

[jazzynico (jazzynico)]

Thanks for taking the time to file a report!

Not reproduced on Windows XP (32-bit), Inkscape 0.91, trunk rev. 14998 (official devlibs) and trunk rev. 14640 (experimental gcc5.1 devlibs).

The following reports seem to be at least related:
Bug #1522085 "Crash when shift+clicking on arc/segment node (ellipse tool)"
Bug #1530272 "shift click on rounded star crashes"
Bug #1594877 "crashes on shift+click rectangle rounding"

@64-bit Windows users, could you please test an experimental version (based on updated dependencies) available at ftp://download.tuxfamily.org/inkscape/win64/ and report back if it's fixed or not? Thanks!

[Lars Johansen (larsmjo)]

Same problem/crash here with Shift+click to remove rectangle rounding:
Was just following the tutorial-shapes.svg

Inkscape 0.91 r13725

OS: Windows 10 Pro, x64, ver. 1511, Build 10586.420

[Lars Johansen (larsmjo)]

Rectangle:
Shift+click to remove rounding - crash 6 out of 10
Ctrl+click to equal rounding - crash 8 out of 10

Circle/Ellipse:
Shift+click to close circle/ellipse - crash 9 out of 10
Ctrl+click to make a circle from an eclipse - crash 8 out of 10

Star/Polygon:
Shift+click to remove rounding - crash 4 out of 10
Ctrl+click to remove skew - crash 7 out of 10
Alt+click to remove randomization - crash 8 out of 10

Spiral:
Shift+click to move inner handle to center - crash 9 out 10
Alt+click to reset divergence - crash 9 out of 10

-----------------------
Inkscape 0.91+devel 64bit r14950 (Inkscape 0.92pre1_64bit r14950)
OS: Windows 10 Pro, x64, ver. 1511, Build 10586.420
(this version have slow startup around 15 sec. on a QuadCore2.4GHz)

[jazzynico (jazzynico)]

Attaching backtrace from duplicate bug #1672543.

[Mc (mc...)]

reproduced on 0.92.x but can't reproduce on master (please feel free to reopen with repro steps on master if needed)

[Patrick Storz (ede123)]

This is actually a pretty annoying class of bugs in 0.92.x - even if it's fixed in master we'd want to backport the fix for 0.92.4, but I couldn't find the commit that fixed it, yet (so maybe it is not fixed at all or is gtk2-specific).

[Sylvain Beucler (beuc)]

(Apparently another report is #1522085.)

I eventually tracked the bug down to a "knot handler" that triggers various events that eventually delete it while it's still processing the click event.
(KnotHolder::knot_clicked_handler -> ShapeEditor::event_attr_changed -> ~KnotHolder)

AFAICS the related upstream commit is 1d2fa48c9a62c4929264cf5b59907f8d4f0e55b5
It introduces several other changed that are based on a newer code base.

The attached patch is a subset of that commit and fixes the issue, although I only tested in minimally.

I hope this will stabilize Inkscape until the next upstream release :)

[Sylvain Beucler (beuc)]

Same patch without the debug trace.

[Sylvain Beucler (beuc)]

Sorry, right patch attached again.
I spent too much time on this and need some sleep ;)

[Sylvain Beucler (beuc)]

Discussion at https://gitlab.com/inkscape/inkscape/merge_requests/377 :)

[Patrick Storz (ede123)]

Based on discussion in the linked MR I created [1] which was merged into master now. If no regressions are found I'm going to merge [2] into 0.92.x which is a back-port of that change.

[1] https://gitlab.com/inkscape/inkscape/merge_requests/377
[2] https://gitlab.com/inkscape/inkscape/merge_requests/387

[Patrick Storz (ede123)]

[2] above merged now, therefore fixed in 0.92.x in
  https://gitlab.com/inkscape/inkscape/commit/17ff0a35f03f00bd5d1d044165a75591fa5a2d97