Duplicating a Power Stroke LPE is a destructive operation.

Summary:

If you take a path (e.g., circle), apply a Power Stroke effect, duplicate it and then delete the new copy, the first Power Stroke gets irreversibly "corrupted".

Steps to reproduce:

  • open Inkscape
  • draw a circle
  • go to path effects (Path > Path Effects...)
  • add Live Path Effect and choose Power Stroke
  • in the Path Effects panel, select the downward pointing chevron (next to the trash can) to show the drop-down menu with "Duplicate, Flatten, Set custom defaults, Set Favorite". Pick "Duplicate".
  • on the newly created Power Stroke effect, select the trash can icon to remove the effect.
  • on the remaining Power Stroke effect, increase the width multiplier at will.

What happened?

You will se that the stroke has now doubled. The width multiplier seems to be affecting the width of a transparent stroke, sandwiched between two lines with a fixed width.

Addendum: please not that this effect stacks. After getting the double line, if you duplicate it once, and then duplicate the new instance of the effect, and then remove the one created last (should be the third one), you'll end up with 4 lines in total.

What should have happened?

Duplicating the first effect shouldn't have broken the first instance of that effect.

Sample attachments:

After adding the first power stroke:

ink1

After duplicating the effect, deleting it, and increasing the width multiplier:

ink2

Version info

Inkscape 1.3 (0e150ed6c4, 2023-07-21)

    GLib version:     2.76.4
    GTK version:      3.24.38
    glibmm version:   2.66.6
    gtkmm version:    3.24.7
    libxml2 version:  2.11.4
    libxslt version:  1.1.38
    Cairo version:    1.17.7
    Pango version:    1.50.14
    HarfBuzz version: 8.0.1

    OS version:       Windows 11 22H2