#### Summary: If a ellipse with transform="scale(-1)" is used in a boolean operation, its shape gets distorted. #### Steps to reproduce: <!-- Describe what you did (step-by-step) so we can reproduce: --> - open Inkscape - create a circle/ellipse - scale it over zero (e.g. drag a scaling corner arrow over the opposite corner arrow) - duplicate it and shift the duplicate horizontally so that the two overlap a bit. - select both circles and choose Path > Union #### What happened? - The resulting shape does not look like two circles combined (some of the smooth nodes became corners) #### What should have happened? - I expect a path with only two corner nodes and six smooth nodes Sample attachments:  #### Version Info: ``` - Inkscape Version: ... 1.0.2 (e86c870879, 2021-01-15) - Operating System: ... Gentoo Linux - Operating System version: ... desktop - 17.1 - stable ```