edit: Fix a corner case

There is one corner case which is not properly handled by the "edit"
command. If a patch deletes a file, and the user calls "quilt edit"
on that file but does not actually add anything back to it, "quilt
remove" is called on the file when the editor exits. This causes
the file to be restored to its original state before the patch deleted
it. The user never asked for that, so the file should be left to its
deleted state in this case. The file must only be removed from the
patch if it was not part of the patch originally.

The same problem would occur if the editor deleted the file. In
general text editors don't do that, they'd leave an empty file
instead, but nothing prevents them from actually deleting the file so
we should handle this case properly too.

0 files changed, 0 insertions, 0 deletions