Guillotine export regions vertically flipped in 1.0

Steps to replicate

1. Open Inkscape
2. Create New Template > default px
3. Import an image and place it off-center
4. Place an off-center horizontal guide

Alternatively, open this file: inkscape-guillotine-test.svg

1. Export > Guillotine

What happened

• Export regions are wrong
• Essentially the guides are flipped across the page
• Note that all guides (regardless of Inkscape preference for y-axis direction) use legacy values for x/y values (so y-axis is always up)

What should have happened

• Export regions match guides

Inkscape Version

Replicated 1.1-dev (3ab2070165, 2020-07-10, custom) Linux Mint 19.1, with extension@a74bf8514f685257051b8fea6cb11c44b3cb361c

Not replicated Inkscape 0.92.5 (6c0c36ef5a, 2020-05-15) Linux Mint 19.1