Lookup a reference to one of the objects in a repostory.
The generated reference is owned by the repository and
should be closed with the git_object_close
method
instead of free'd manually.
The 'type' parameter must match the type of the object in the odb; the method will fail otherwise. The special value 'GIT_OBJ_ANY' may be passed to let the method guess the object's type.
a reference to the object