Merge branch 'as/t4012-style-updates'

* as/t4012-style-updates: t4012: Use test_must_fail instead of if-else t4012: use 'printf' instead of 'dd' to generate a binary file t4012: Re-indent test snippets t4012: Make --shortstat test more robust t4012: Break up pipe into serial redirections t4012: Actually quote the sed script t4012: Unquote git command fragment in test title t4012: modernize style for quoting