Crash when a connector is duplicated and unlinked

[Marc Kruzik]

Steps to reproduce:
- create two shapes
- connect them with a connector
- group the 3 objects (2 shapes and their connector)
- duplicate the group
- move the duplicated group
- unlink the duplicated group
- the duplicated connector goes back to the original connector position
- select the original group
- move the original group
- crash

I'm using Inkscape 0.92.1 r15371 on an old Windows XP SP3.

[Alvin Penner (apenner)]

reproduced on Windows 10, Inkscape 0.92.3 (2405546, 2018-03-11)

backtrace:
Program received signal SIGSEGV, Segmentation fault.
0x017fb910 in libinkscape_base!_ZN5Avoid7ConnRef15makePathInvalidEv () from c:\program files (x86)\inkscape\libinkscape_base.dll
(gdb) bt
#0 0x017fb910 in libinkscape_base!_ZN5Avoid7ConnRef15makePathInvalidEv ()
   from c:\program files (x86)\inkscape\libinkscape_base.dll
#1 0x01707c2f in libinkscape_base!_ZN13SPConnEndPair24tellLibavoidNewEndpointsEb ()
   from c:\program files (x86)\inkscape\libinkscape_base.dll
#2 0x01707da7 in libinkscape_base!_ZN13SPConnEndPair23reroutePathFromLibavoidEv ()
   from c:\program files (x86)\inkscape\libinkscape_base.dll
#3 0x0e02e9c0 in ?? ()
#4 0x016963f4 in libinkscape_base!_Z25sp_selection_apply_affinePN8Inkscape9SelectionERKN4Geom6AffineEbbb ()
   from c:\program files (x86)\inkscape\libinkscape_base.dll
#5 0x01698028 in libinkscape_base!_Z17sp_selection_movePN8Inkscape9SelectionEdd ()
   from c:\program files (x86)\inkscape\libinkscape_base.dll
#6 0x01330319 in libinkscape_base!_ZN8Inkscape2UI5Tools10SelectTool12root_handlerEP9_GdkEvent ()
   from c:\program files (x86)\inkscape\libinkscape_base.dll
#7 0x01346d1f in libinkscape_base!_ZN8Inkscape2UI5Tools29sp_event_context_root_handlerEPNS1_8ToolBaseEP9_GdkEvent ()
   from c:\program files (x86)\inkscape\libinkscape_base.dll
#8 0x08e866b0 in ?? ()
#9 0x61a4e0aa in ?? () from c:\program files (x86)\inkscape\libgtk-win32-2.0-0.dll
#10 0x63c45f03 in ?? () from c:\program files (x86)\inkscape\libgobject-2.0-0.dll
#11 0x63c582cd in ?? () from c:\program files (x86)\inkscape\libgobject-2.0-0.dll
#12 0x63c5fbdd in ?? () from c:\program files (x86)\inkscape\libgobject-2.0-0.dll
#13 0x63c60937 in ?? () from c:\program files (x86)\inkscape\libgobject-2.0-0.dll
#14 0x61b69509 in ?? () from c:\program files (x86)\inkscape\libgtk-win32-2.0-0.dll
#15 0x61b7de2e in ?? () from c:\program files (x86)\inkscape\libgtk-win32-2.0-0.dll
#16 0x61b80abf in ?? () from c:\program files (x86)\inkscape\libgtk-win32-2.0-0.dll
#17 0x61a4e0aa in ?? () from c:\program files (x86)\inkscape\libgtk-win32-2.0-0.dll
#18 0x63c45f03 in ?? () from c:\program files (x86)\inkscape\libgobject-2.0-0.dll
#19 0x63c57d17 in ?? () from c:\program files (x86)\inkscape\libgobject-2.0-0.dll
#20 0x63c5fbdd in ?? () from c:\program files (x86)\inkscape\libgobject-2.0-0.dll
#21 0x63c60937 in ?? () from c:\program files (x86)\inkscape\libgobject-2.0-0.dll
#22 0x61b695d3 in ?? () from c:\program files (x86)\inkscape\libgtk-win32-2.0-0.dll
#23 0x61a4c30b in ?? () from c:\program files (x86)\inkscape\libgtk-win32-2.0-0.dll
#24 0x61a4c60c in ?? () from c:\program files (x86)\inkscape\libgtk-win32-2.0-0.dll
#25 0x6c5792b4 in ?? () from c:\program files (x86)\inkscape\libgdk-win32-2.0-0.dll
#26 0x687f3ad7 in ?? () from c:\program files (x86)\inkscape\libglib-2.0-0.dll
#27 0x687f3cd8 in ?? () from c:\program files (x86)\inkscape\libglib-2.0-0.dll
#28 0x687f4172 in ?? () from c:\program files (x86)\inkscape\libglib-2.0-0.dll
#29 0x61a4b5e9 in ?? () from c:\program files (x86)\inkscape\libgtk-win32-2.0-0.dll
#30 0x0040615f in ?? ()
#31 0x0040e3c5 in ?? ()
#32 0x004013cb in ?? ()
...

[Xortex (xortex)]

Bug should now be fixed: https://gitlab.com/inkscape/inkscape/merge_requests/323