Aliased selection bounding error + bounding box size changes based on canvas position

[Roly Poly Goblinoli]

Aliased selection bounding error + bounding box size changes based on canvas position

Version 5.1

Windows 10, any OS will repro

 

Current behavior
If you select and rotate certain sizes of pixels while using aliased selection bounds, you get unexpected behavior in the selection bounds, which changes based on the position of the selection on the canvas. If you then drag that selection around, it will alternate between computing a 1x7 line and a 2x7 rectangle just based on the canvas position alone! This isn't just visual; if you press enter then it will actually commit those pixels. Here's a picture of that:


This error repros with all sampling methods.

The current workaround is to copy to a new image and rotate, or new layer, rotate, then move it back.

 

Reproduction Steps (100% repro)

1. Open Paint.net
2. Rectangle select a 7x2 or 2x7 region anywhere
3. Rotate it 90 degrees in any direction (use shift so it snaps perfectly to the angle)

Notice that the selection bounds are now 3x7 or 7x3; respectively
 

Expected behavior

My 2x7 selection when rotated 90 degrees should be 7x2 pixels, not 7x3.
It also should not change bounding box size while it's being dragged around the canvas.