Sub-segment assignment loss when painting sub-segments.

[Evan555alpha]

Description
For Fallout 4, I have an armour-piece outfit that I have been creating for a while now. I have been creating the sub-segment data through Outfit Studio v5.2.0.0. I have run into a scenario where, upon painting the last few faces on the last sub-segment I am trying to create, all sub-segment assignments are subsequently cleared.
All sub-segments remain in the top right window, but each sub-segment's assigned faces becomes blank, and I have to start over from whenever the project was last saved.
The expected behaviour is for that to, well, not happen.

How to reproduce

1. Have outfit that has no sub-segments.

2. Hand-assign sub-segments. In my case it's segments 0 through 6, and then sub-segments 0 through 4 for both segments 5 and 6, for the legs.

3. Have an area like so, where there's three sub-segments; one that is painted the way you want, one that you are painting over, and one that you are trying to paint. In my case, I had already properly assigned all other sub-segments the way I wanted. This was the last little bit that I needed to do.
   

4. Attempt to paint the last of the final sub-segment. Upon doing so, the neighbouring sub-segment will become a slightly different colour. This indicates that sub-segment assignment is about to be lost.
   
   

5. Hit "Apply" in the top right. All sub-segment assignments will be lost. If one does not save after this happens, one can reload the project to go back to what the sub-segment assignments were at the time of last saving.
   

If needed, I can provide the project file(s) these images were taken from, in the event that it's something wrong with the project itself.

[ousnius]

@Evan555alpha I've played around with it a bit and this seems to happen when you right-click the top segment (not sub segment) to insert the new sub segments via the context menu. The internal IDs get shuffled the wrong way.

If you always right-click the newly added sub segment to add the next sub segment (instead of the parent segment), then it will work. I will think of what to do to fix it.

[ousnius]

This should be fixed for the next version, thanks for the report.

[sts1skj]

@Evan555alpha I was unable to reproduce your bug by trying to follow your instructions, but I was able to trigger it. The key trigger was this: hitting apply while the last segment or subsegment was empty. (By empty, I mean it had no triangles assigned to it.)

Hopefully I have finally fixed this bug in ousnius/nifly#26