Change Details

Most importantly: * Avoid unsafe use of `-a` and `-o` operators in `test` expressions. * Remove a hack intended to ease the transition from Perl 22 years ago. MFC after: 1 week

Most importantly: * Make local variables local. * Avoid unsafe use of `-a` and `-o` operators in `test` expressions. * Remove a hack intended to ease the transition from Perl 22 years ago. MFC after: 1 week

Most importantly: * Make local variables local. * Avoid unsafe use of `-a` and `-o` operators in `test` expressions. * Remove a hack intended to ease the transition from Perl 22 years ago. MFC after: 1 week