MBL/VBL are misaligned with the map image when importing a cropped Universal VTT map

[kwvanderlinde]

Describe the bug
When exporting a Universal VTT map from Dungeondraft, there is an option to crop the map. However, when the map is imported into MapTool, the map image and the MBL/VBL are not aligned with each other, being offset by the amount of the cropping.

To Reproduce
Steps to reproduce the behavior:

1. Import a UVTT map produced using a cropped export from Dungeondraft.
2. Accept the defaults in the "Imported Map Properties" dialog.
3. Select VBL tools from the toolbar
4. See that the walls' VBL/MBL does not line up with the walls in the image.

Expected behavior
VBL/MBL on cropped UVTT maps are aligned with the map image.

Screenshots
Importing the provided uncropped map gives the correct results:

But when the map is cropped by 2 cells each side, we get this instead:

MapTool Info

• Version: 1.9.3
• Install: New

Desktop (please complete the following information):

• OS: Linux Mint
• Version 20.2

Additional context
This zip contains a cropped UVTT map, the uncropped version of the same map, and a campaign file that with both maps imported: cropped uvtt example.zip

Comparing the contents of the *.dd2vtt files shows that the only differences are to "resolution" > "map_origin" and "resolution" > "map_size", and of course the contents of "image" are different as well.

[Phergus]

Should be working as expected now:

PR #3117 fixes: Adjusts LOS blocking for maps cropped on export from Dungeondraft. Also corrects the grid offset to match for maps cropped not cropped on grid boundaries.

@kwvanderlinde would you like to test the fix?

[kwvanderlinde]

Looks good. I've verified that the MBL/VBL is now aligned with the map image, and that the grid is aligned with the map image. Tested with crops that are completed aligned, completely unaligned or partially aligned with grid boundaries.

[Phergus]

Excellent. Thanks!