[PATCH 11/38] view: simplify _parent_headers

[Eric Wong]

Having References but lacking In-Reply-To is an uncommon case
with email, nowadays.  So just rely on ->linkify_mids to handle
linkification and HTML escaping  Furthermore, headers are short
enough to return as-is (and rely on CoW improvements in Perl
5.1x) since linkify_mids needs to operate on an independent
string, anyways.
---
 lib/PublicInbox/View.pm | 39 ++++++++++-----------------------------
 1 file changed, 10 insertions(+), 29 deletions(-)

diff --git a/lib/PublicInbox/View.pm b/lib/PublicInbox/View.pm
index c6fd05cc..3980ed91 100644
--- a/lib/PublicInbox/View.pm
+++ b/lib/PublicInbox/View.pm
@@ -740,8 +740,7 @@ sub _msg_page_prepare_obuf {
                $ctx->{-linkify}->linkify_mids('..', \$s, 1);
                $rv .= $s;
        }
-       _parent_headers($ctx, $eml);
-       $rv .= "\n";
+       $rv .= _parent_headers($ctx, $eml);
        1;
 }
 
@@ -795,32 +794,21 @@ sub _parent_headers {
        my ($ctx, $hdr) = @_;
        my @irt = $hdr->header_raw('In-Reply-To');
        my $refs;
-       if (@irt) {
-               my $s = '';
-               $s .= "In-Reply-To: $_\n" for @irt;
-               $ctx->{-linkify}->linkify_mids('..', \$s);
-               ${$ctx->{obuf}} .= $s;
-       } else {
+       my $s = '';
+       if (!@irt) {
                $refs = references($hdr);
-               my $irt = pop @$refs;
-               if (defined $irt) {
-                       my $html = ascii_html($irt);
-                       my $href = mid_href($irt);
-                       ${$ctx->{obuf}} .= <<EOM;
-In-Reply-To: &lt;<a\nhref="../$href/">$html</a>&gt;
-EOM
-               }
+               $irt[0] = pop(@$refs) if scalar @$refs;
        }
+       $s .= "In-Reply-To: $_\n" for @irt;
 
        # do not display References: if search is present,
        # we show the thread skeleton at the bottom, instead.
-       return if $ctx->{ibx}->over;
-
-       $refs //= references($hdr);
-       if (@$refs) {
-               $_ = linkify_ref_no_over($_) for @$refs;
-               ${$ctx->{obuf}} .= 'References: '. join("\n\t", @$refs) . "\n";
+       if (!$ctx->{ibx}->over) {
+               $refs //= references($hdr);
+               $s .= 'References: <'.join(">\n\t<", @$refs).">\n" if @$refs;
        }
+       $ctx->{-linkify}->linkify_mids('..', \$s); # escapes HTML
+       $s .= "\n";
 }
 
 # appends to obuf
@@ -901,13 +889,6 @@ EOF
        $ctx->zmore($skel .= msg_reply($ctx, $hdr)); # flushes obuf
 }
 
-sub linkify_ref_no_over {
-       my ($mid) = @_;
-       my $href = mid_href($mid);
-       my $html = ascii_html($mid);
-       "&lt;<a\nhref=\"../$href/\">$html</a>&gt;";
-}
-
 sub ghost_parent {
        my ($upfx, $mid) = @_;