Crash on undo of unnecessary relinking of filter primitive (Filter Editor)

Summary:

Just found out a way to get the Filter Editor to 'Segmentation fault' on an undo, due to it recording an action that really wasn't done.

Steps to reproduce:

  1. Open attached file.
  2. Select the ellipse.
  3. Open the Filter Editor and expand it so you can see all the connections for the "Metallized Paint" filter.
  4. Select the "Specular Lighting", right click, and duplicate.
  5. Now select the 'new' "Specular Lighting", which should be at the bottom of the tree.
  6. Now left click on the little arrow and drag it up to attempt to connect it to the "Gaussian Blur" right above the original "Specular Lighting" as shown here. (NOTE: it's already connected per the tree, but just do it anyways.)connections
  7. Attempt to undo.

What happened?

Inkscape crashes and creates an emergency save file.

What should have happened?

Inkscape shouldn't have crashed, as Step 6 shouldn't have been recorded since the 2nd "Specular Lighting" was already attached to that "Gaussian Blur" originally.

Sample attachments:

crash1.svg

Version Info:

- Inkscape Version: 1.0.1 (3bc2e813f5, 2020-09-07) x64
- Operating System: Windows
- Operating System version: Windows 7 SP1 x64
Edited by Nathan Lee