Changing display units changes paths with ruler LPE on reopen
Issue split from #1674
Steps to reproduce:
- open Inkscape
- create a straight line
- add a ruler LPE
- save
- open document properties
- change display units to inches (or something different if already inches)
- save as a different file
- close
- reopen both files to compare
What happened?
- size is dependent on display units (and isn't correct either)
What should have happened?
- size is independent of display units, and should reflect width/height values in the svg root
Sample attachments:
Following instructions above
| mm | comparison png | in |
|---|---|---|
| ruler-units-mm.svg |  |
ruler-units-in.svg |
Other test cases taken from #1674
