[[!comment format=mdwn
 username="joey"
 subject="""comment 1"""
 date="2018-08-06T19:49:06Z"
 content="""
Great bug report!

There is a general data loss problem in this scenario, it's not specific to
group changes at all. Changes that were only present in a sibling git-annex
branch are not being preserved when the repository updates its git-annex
branch index file for a transition.

The index file lacking those changes then gets committed with the sibling
branches as parent(s). So the changes are effectively reverted.

The root cause is that the handleTransitions uses getRaw
to get the contents of files. That uses git cat-file git-annex:$file, which
gets the version last committed to the git-annex branch,
not the version from the git-annex branch index file. And handleTransitions is
run after all sibling branches have been union merged in the index file
but not committed yet. 

The fix is to instead use git cat-file :$file, so it will get the version
from the index. 
"""]]
