Bantracker duration parsing could be improved

[ilbelkyr]

Currently, if an op sets a ban duration in a format eir doesn't recognize (e.g. ~1y thinking it will be a year-long ban), this will silently assume the ban to expire in just 1 (which is assumed to be minutes by default). It'd probably be more desirable to complain to the commenting op.

The relevant code is in sub calc_time:

eir/scripts/bantracker.pl

Lines 718 to 740 in 6a267fb

	sub calc_time {
	# take a dircbot style time specification
	# and return a time in seconds
	my $spec=shift @_;
	my $time=0;
	while ($spec =~ /^~?(\d+)([dhmsw]?)/) {
	if ($2 eq 'm') {
	$time+=$1*60;
	} elsif ($2 eq 'h') {
	$time+=$1*3600;
	} elsif ($2 eq 'd') {
	$time+=$1*86400;
	} elsif ($2 eq 'w') {
	$time+=$1*604800;
	} elsif ($2 eq 's') {
	$time+=$1;
	} else {
	$time+=$1*60;
	}
	$spec=$';
	}
	return $time;
	}

Allowing 'y' to indicate years would only be a partial solution as eir would still accept other invalid inputs. While it could be argued that those are the commenting op's problem, I feel it'd be nicer to tell them what they're doing wrong in that case.

Side note: The regex used uses a \d character class. This probably ought to be [0-9] to avoid matching Unicode digits that aren't handled as numbers by Perl, such as ٧ (U+0667, ARABIC-INDIC DIGIT SEVEN). Alternatively, the /a modifier introduced in Perl 5.14 could be used.