git am oddity

Hi,

I noticed something very odd with git am, and have been able to narrow it down to a minimal example.

 git init tmp
 cd tmp
 mkdir -p foo/bar/baz
 cd foo/bar/baz
 echo file > file
 git add file
 git commit -m "1"
 echo other > other
 echo more >> file
 git add file other
 git commit -m "my test"
 git format-patch HEAD~..
 git reset --hard HEAD~
 # apply the patch in the current directory, chop off the leading directories
 git am -3 -p 3 0001-my-test.patch
 cd ../../..
 git ls-files

Expected output: foo/bar/baz/file foo/bar/baz/other

Actual output: baz/other # the file addition was applied to the root of the repository, instead of the current directory foo/bar/baz/file # the file modification was correctly applied, yay

Is this expected behavior?