[PATCH 9/9] smsg: parse_references: micro-optimization

[Eric Wong <e@80x24.org>]

With Perl 5.10+, we can rely on the defined-or-assignment (//=)
operator to avoid repeatedly rewriting an SV.

This may not provide a measurable difference here, but
it's more consistent with current style where things like
commit a05445fb400108e60ede7d377cf3b26a0392eb24
("config: config_fh_parse: micro-optimize") provide a measurable
improvement.
---
 lib/PublicInbox/Smsg.pm | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/PublicInbox/Smsg.pm b/lib/PublicInbox/Smsg.pm
index 2b72e8b5..b4cc2ecb 100644
--- a/lib/PublicInbox/Smsg.pm
+++ b/lib/PublicInbox/Smsg.pm
@@ -83,7 +83,7 @@ sub parse_references ($$$) {
 			warn "References: <$ref> too long, ignoring\n";
 			next;
 		}
-		push(@keep, $ref) unless $seen{$ref}++;
+		$seen{$ref} //= push(@keep, $ref);
 	}
 	$smsg->{references} = '<'.join('> <', @keep).'>' if @keep;
 	\@keep;