So that took way too long... don't try to retrieve lock information if the file doesn't exist in head as that unsurprisingly fails.
So that took way too long... don't try to retrieve lock information if the file
doesn't exist in head as that unsurprisingly fails.

Fix diffs with deletions.


ashirley/reviki,CoreFiling/reviki,paulcadman/reviki,CoreFiling/reviki,ashirley/reviki,strr/reviki,CoreFiling/reviki,paulcadman/reviki,ashirley/reviki,strr/reviki,CoreFiling/reviki,ashirley/reviki,paulcadman/reviki,CoreFiling/reviki,strr/reviki,strr/reviki,strr/reviki,ashirley/reviki,paulcadman/reviki