t / t4013 / diff.log_-SF_master_--max-count=2on commit update-index --split-index: do not split if $GIT_DIR is read only (a0a9675)
   1$ git log -SF master --max-count=2
   2commit 9a6d4949b6b76956d9d5e26f2791ec2ceff5fdc0
   3Author: A U Thor <author@example.com>
   4Date:   Mon Jun 26 00:02:00 2006 +0000
   5
   6    Third
   7$