Merge branch 'jk/hash-object-fsck'

"git hash-object" now checks that the resulting object is well
formed with the same code as "git fsck".

* jk/hash-object-fsck:
  fsck: do not assume NUL-termination of buffers
  hash-object: use fsck for object checks
  fsck: provide a function to fsck buffer without object struct
  t: use hash-object --literally when created malformed objects
  t7030: stop using invalid tag name
  t1006: stop using 0-padded timestamps
  t1007: modernize malformed object tests

diff --cc object-file.c
Simple merge

diff --cc t/t6300-for-each-ref.sh
Simple merge