+my $orig = join(', ', @addr);
+my $res = PublicInbox::View::fold_addresses($orig.'');
+isnt($res, $orig, 'folded result');
+unlike($res, qr/l,\n\tf/s, '"last, first" no broken');
+my @nospc = ($res, $orig);
+s/\s+//g for @nospc;
+is($nospc[0], $nospc[1], 'no addresses lost in translation');
+my $tws = PublicInbox::View::fold_addresses($orig.' ');
+# (Email::Simple drops leading whitespace, but not trailing)
+$tws =~ s/ \z//;
+is($tws, $res, 'not thrown off by trailing whitespace');