Merge branch 'maint'

* maint: sha1_file.c: resolve confusion EACCES vs EPERM sha1_file: avoid bogus "file exists" error message git checkout: don't warn about unborn branch if -f is already passed bash: offer refs instead of filenames for 'git revert' bash: remove dashed command leftovers git-p4: fix keyword-expansion regex fast-export: use an unsorted string list for extra_refs Add new testcase to show fast-export does not always exports all tags