pre-commit hook, non-zero exit status and dangling objects

Hi,

After pre-commit returned non-zero status, I could see new dangling objects in my repo. I think it's not normal, because pre-commit is often used for checking formation of source files and after changing this files, hash of object will be also changed and even after successfull commit dangling object will be still alive.

-- With best regards, Sergey I. Sharybin