Connector tool: Impossible to connect object placed on top of another object

Migrated from: https://bugs.launchpad.net/inkscape/+bug/1433115

Steps to reproduce:

  • open Inkscape
  • Add a background shape
  • Add a shape "1"
  • Add a shape "2" on top of the background shape (example in attached file)
  • Try to create a diagram connector from 1 to 2

What happened?

  • The diagram connector cannot be connected to shape 2, because it is on top of a background shape -- the handle to connect to shape 2 does not appear
  • Instead only the handle of the background shape appears

What should have happened?

Expected behavior:

  • The diagram connector can be connected both to shape 2 and the background shape, however the user desires
  • The shape in the foreground takes precedence over the background shape, not vice-versa

Workarounds:

  • Move shape 2 to an empty area, then move back --> This is annoying
  • Move shape 2 below the background shape and connect -> this works !?

Inkscape Version and Operating System:

  • Inkscape Version: 1.1-dev (12e2a09, 2020-02-19)
  • Operating System: Windows 10
  • Operating System version: 10.0.18362

connect_a_box_on_top_of_another.svg

Migration info

  • Reproduced on Windows XP, Inkscape 0.91 and trunk rev. 14023.
  • Not reproduced with 0.48.5, Windows XP
  • not reproduced with rev 10326 (merge of cairo renderer),
  • not reproduced with rev 10578 (just before the merge of the rendering cache branch),
  • reproduced with rev 10579 (merge of rendering cache),
  • reproduced with rev >= 10588 (just before the removal of libnr in 10589); the regression is possible related to the changes for the renderer's caching (though disabling the cache e.g. with current trunk does not restore the behavior known from earlier releases).
  • Reproduced with Inkscape 0.91 r13725 and 0.91+devel r1491 on OS X 10.7.5.