This makes our implementation of which work with shell builtins that also exist
as external commands (like "true"). Fixes issue1101 test that would send emails
since the SENDMAIL override didn't work.
1 patch for repository http://darcs.net/screened:
Sat Sep 22 18:52:53 CEST 2012 Petr Rockai <me@mornfall.net>
* Tests: Use type -P instead of -p for "which".