Recatangle Select with Repalce and Union mode gets one selection out of sync

[grofaty]

Tested on 1.7+r1122-202007302144~ubuntu18.04.1:
1. Rectangle Select and mark some area on canvas.
2. Press CTRL+left mouse to mark another selection that overlaps with previous selection (this triggers Union selection mode and mark some area on canvas.
3. Move Selection and move market area around little bit.
4. Click on Rectangle Select tool.
5. Resize selection and rectangle part of step 1 selection gets out of sync (it "jumps" little bit).

I have recorded a screencast to easily demonstrate.

[grofaty (grofaty)]

I tested this little bit and the same problem appears with all other Selection Modes, so in step 2 instead of Union mode select any of the Exclude, Xor, Intersect mode and the problem in step 5 then result in "jump" of first selection.

[grofaty (grofaty)]

Additional testing. The same problem appears if in step 1 and step 4 Ellipse Select is selected instead of Rectangle Select, the "jump" of first selection.

[Cameron White (cameronwhite91)]

Fixed by https://github.com/PintaProject/Pinta/commit/7925b8416ed33138e97c06495a563ed89886b6e0

[grofaty (grofaty)]

I have retested in 1.7+r1123-202007312014~ubuntu18.04.1 and I can confirm it is fixed now.