bug in name-rev on linux-2.6 repo?

~/src/linux-2.6$ git name-rev a1de02dccf906faba2ee2d99cac56799bda3b96a
 a1de02dccf906faba2ee2d99cac56799bda3b96a undefined


 git --version
 git version 1.7.0.4


~/src/linux-2.6$ git branch | grep ^*
* master

never happened to me before but don't seem to get ancestry of
that ext4 merge, can you check what is wrong there?
bug verified also on older git 1.6.5

thanks

-- 
maks