[BUG] "git apply --index" with missing --directory option silently does nothing

When applying a patch file for a subtree of a git repo, where was required is "git apply --index --directory=...", if the user forgets to add the --directory flag, then git should bomb out saying it cannot apply the patch.

But what happens is that nothing happens, and git stays silent about having done nothing:

~/softs/tmp/linux-2.6.32$ git rev-parse --git-dir /home/localadm/softs/tmp/.git ~/softs/tmp/linux-2.6.32$ bzcat /home/localadm/Downloads/patch-2.6.32.28.bz2 | git apply --index --whitespace=nowarn ~/softs/tmp/linux-2.6.32$ echo $? 0 ~/softs/tmp/linux-2.6.32$ git status # On branch master nothing to commit (working directory clean)