Caption is added twice.

[scofalik]

At the moment, there is a callback that adds <caption> to <image> whenever <image> without <caption> is inserted to the document. Unfortunately, there is a small bug in that fixer, which causes adding redundant <caption> (and it also makes the editor throw :P).

So the problem is when the change comes from OT (redo is taken care of because fixer checks type == 'insert'). Client A adds an image and generates <caption> using fixer.

Then on client B, first, you get the InsertOperation that inserts just the <image>. The fixer checks it and sees that empty <image> is added, so it adds the <caption>. But then you get the "fixer operation" from client A which adds additional <caption>.

There are two solutions possible.

1. In batch.document.enqueueChanges block, check if the <image> is still empty, before adding second <caption>.
2. Do not fix if batch.type is transparent.

I prefer 1 solution, at least for now. We haven't discussed how fixers and problems like this should be solved for OT yet (similar case will be with possible auto embed feature -- converted link should not be replaced twice).