### Please describe the problem.
After having added new content (SHA1E backend), when trying to commit, git commit fails with the following error:

[[!format sh """
(Recording state in git...)
error: invalid object 100644 5d471129a031f0f493de3736eaea6f2f4056aeee for '000/091/WORM-s1493-m1321288671--scrapbook%data%20111114173520%horiz-menu-tab-r_001.png.log'
fatal: git-write-tree: error building trees
git-annex: failed to read sha from git write-tree
"""]]

The commit subsequently fails and the index is left as is. When I did git-annex add, I got the same error, but the additions seem to have been staged, at least.

What’s curious about this is that I migrated all keys to SHA1E earlier and dropped all WORM keys. git annex info also says that all my keys are SHA1E.

Can this be related to your changes to the WORM backend? I upgraded to git-annex 5.20140818 today. Rolling back to 5.20140716 didn’t allow me to commit, either, though.

Any way I could resolve this? I don’t want to git reset for now, since this will leave the added objects in the annex store.

### What version of git-annex are you using? On what operating system?
git-annex 5.20140818

Linux 3.16.1
