Version comparison in packages_per_pmfile seems broken in some cases

[charsbar]

The $version at the following line (

pause/lib/PAUSE/pmfile.pm

Lines 299 to 305 in b54e8bd

	$ppp->{$pkg}{version} =
	$version
	if ($version||0)
	> $ppp->{$pkg}{version} ||
	($version||"")
	gt $ppp->{$pkg}{version};
	}

) usually matches the version stored in $ppp->{$pkg}{version} , but sometimes the $version may be stringified "undef" which comes from the line

pause/lib/PAUSE/pmfile.pm

Line 376 in b54e8bd

$result = "undef" unless defined $result;

(via

pause/lib/PAUSE/pmfile.pm

Line 128 in b54e8bd

$self->{VERSION} = $version;

and

pause/lib/PAUSE/pmfile.pm

Line 199 in b54e8bd

my $version = $self->{VERSION};

).
It's probably better to add a helper function to compare versions that treats stringifiied undef as undef or 0.