Bug: stash staged file move loses original file deletion

Git version 2.8.0 (sorry can't update to more recent on my machine) on Ubuntu.

After moving a file, if the new file is in the index but the deletion of the old file is not staged, git stash loses the deletion operation. Repro:

1. git mv a b
This will have both the "deletion" and the "file added" in the index

2. git stash; git stash pop
Now file a is still in the index, but file b deletion is not staged.

3. git stash; git stash show -v
This will show that the deletion operation is not in the stash

4. git stash pop
Again confirms the issue, file a is in the index, but file b is
present and unmodified in the working directory.