Branch merge error: "Cannot read properties of undefined (reading root)"

[brollb]

When running a plugin that created a node (which children and attributes but no pointers outside of base), it branched due to collaborative edits. This branch cannot be merged for some reason.

I couldn't find the base but grabbed a commit that should be about right. (It may not be the immediate predecessor but should be close.)

merge_err.zip

[brollb]

base.zip