Autocomplete on user entity with related profile fields breaks on upgrade to 7.x-1.1

Since upgrading from EntityReference 7.x-1.0 to EntityReference 7.x-1.1, the autocomplete on an entity reference field used to reference users via their profile name has stopped working.

After some debugging, I think I have traced this change in behaviour down to this commit:
http://cgit.drupalcode.org/entityreference/commit/?id=8cbef5ee410b36ca1d...

After stepping through the code with a debugger a few times, I am still none the wiser as to why this code breaks our autocomplete view.

For background, the entityreference view is a user view with a relationship to the user profile entity (profile2), so we can pull through the firstname, lastname etc. and search on these values. Reading through the code and the issue it came from, it appears that this commit was intended to actually fix this issue, rather than cause it.

So for our needs, we would like to use the 7.x-1.1 release, as it is a security release and includes other fixes, but would like to remove this commit, so I'll attach a patch that does that. This patch is mainly for our own needs, but may help someone else in the same situation, and will hopefully prompt some further discussion about why the original commit causes the problem in the first place.