Comment 2 for bug 1698048

Would my .hugin help? Attached just in case.

> (Who the heck does such a ..., add mask and immediately delete it)

I found the bug by making two exclude-from-all-images-of-this-lens masks: I was using the masks to control where the CP's are placed. After the CPs are placed and the geometry optimized, I have to remove the masks so I can stitch the pano (in this case using it to align an image stack) without excluding that region of the images from the final result.

But more generally, the bug happens (for me) any time I delete the last of any kind of mask from a list of masks. It doesn't need to be done immediately.

Fortunately the workaround is simple: don't delete the last mask. If I delete the first (or second, as long as it is not the last) it works fine. (This is why I guessed it was a fencepost error...)