viewdiff: use defined checks in more places

It's less cognitive overhead for future readers since I just
looked at it again and thought it was possible for "0" to be returned
(it isn't).

diff --git a/lib/PublicInbox/ViewDiff.pm b/lib/PublicInbox/ViewDiff.pm
index f492b6971981706753480f8bc36554f7cd43b120..fb394b7c430e5b47994f1af91e8c644b673030ef 100644 (file)
--- a/lib/PublicInbox/ViewDiff.pm
+++ b/lib/PublicInbox/ViewDiff.pm
@@ -83,7 +83,7 @@ sub anchor0 ($$$$) {
        # long filenames will require us to check in anchor1()
        push(@{$ctx->{-long_path}}, $fn) if $fn =~ s!\A\.\.\./?!!;
 
-       if (my $attr = to_attr($ctx->{-apfx}.$fn)) {
+       if (defined(my $attr = to_attr($ctx->{-apfx}.$fn))) {
                $ctx->{-anchors}->{$attr} = 1;
                my $spaces = ($orig =~ s/( +)\z//) ? $1 : '';
                $$dst .= " <a\nid=i$attr\nhref=#$attr>" .
@@ -97,7 +97,7 @@ sub anchor0 ($$$$) {
 # returns "diff --git" anchor destination, undef otherwise
 sub anchor1 ($$) {
        my ($ctx, $pb) = @_;
-       my $attr = to_attr($ctx->{-apfx}.$pb) or return;
+       my $attr = to_attr($ctx->{-apfx}.$pb) // return;
 
        my $ok = delete $ctx->{-anchors}->{$attr};
 
@@ -105,10 +105,10 @@ sub anchor1 ($$) {
        # assume diffstat and diff output follow the same order,
        # and ignore different ordering (could be malicious input)
        unless ($ok) {
-               my $fn = shift(@{$ctx->{-long_path}}) or return;
+               my $fn = shift(@{$ctx->{-long_path}}) // return;
                $pb =~ /\Q$fn\E\z/s or return;
-               $attr = to_attr($ctx->{-apfx}.$fn) or return;
-               $ok = delete $ctx->{-anchors}->{$attr} or return;
+               $attr = to_attr($ctx->{-apfx}.$fn) // return;
+               $ok = delete $ctx->{-anchors}->{$attr} // return;
        }
        $ok ? "<a\nhref=#i$attr\nid=$attr>diff</a> --git" : undef
 }