[PATCH 4/4] view: avoid uninitialized var from diff query textarea

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

Rare commits without titles and emails without a Subject: header
should not litter stderr or syslog with uninitialized variable
warnings.
---
 lib/PublicInbox/View.pm | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/PublicInbox/View.pm b/lib/PublicInbox/View.pm
index 275258e3..7ca85a85 100644
--- a/lib/PublicInbox/View.pm
+++ b/lib/PublicInbox/View.pm
@@ -849,7 +849,7 @@ sub thread_skel ($$$) {
 sub dfqry_text ($$) {
 	my ($ctx, $subj) = @_;
 	my $qry_dfblob = delete $ctx->{-qry_dfblob} or return (undef);
-	my @bs = split /["\x{201c}\x{201d}]+/, $subj;
+	my @bs = split /["\x{201c}\x{201d}]+/, $subj // '';
 	my $q = join ' ', (@bs ? ('(') : ()), map {
 		chop if length > 7; # include 1 abbrev "older" patches
 		"dfblob:$_";