I'm not sure it is a bug. It certainly can be an improvement. Code as is does not cause issues although I concur with you that it is at least a strange syntax. It is like this at least since 2009 (commit ba748f7a11e). I'm not sure parse_bool* is the right place to fix it because it could break code. IMHO the problem is that parse_one_reloption() is using the value provided by user; it should test those (abbreviation) conditions and store "true" (for example) as bool value.