view: display redundant headers in permalink

Mail headers can contain multiple headers of any type, so ensure
we don't hide any information we're getting in the per-message
permalink views.

This means it's possible to have multiple From, Date, To, Cc,
Subject, and In-Reply-To headers displayed.

The thread indices are a special case, I guess, since we run
out of space on the line if the headers too long and tools like
mutt only show the first one.

1 files changed, 29 insertions, 0 deletions

diff --git a/lib/PublicInbox/Linkify.pm b/lib/PublicInbox/Linkify.pm
index 175f8d72..5b83742c 100644
--- a/lib/PublicInbox/Linkify.pm
+++ b/lib/PublicInbox/Linkify.pm
@@ -89,4 +89,33 @@ sub linkify_2 {
         $_[1];
 }
 
+# single pass linkification of <Message-ID@example.com> within $str
+# with $pfx being the URL prefix
+sub linkify_mids {
+        my ($self, $pfx, $str) = @_;
+        $$str =~ s!<([^>]+)>!
+                my $msgid = PublicInbox::Hval->new_msgid($1);
+                my $html = $msgid->as_html;
+                my $href = $msgid->{href};
+                $href = ascii_html($href); # for IDN
+
+                # salt this, as this could be exploited to show
+                # links in the HTML which don't show up in the raw mail.
+                my $key = sha1_hex($html . $SALT);
+                $self->{$key} = [ $href, $html ];
+                '<PI-LINK-'. $key . '>';
+                !ge;
+        $$str = ascii_html($$str);
+        $$str =~ s!\bPI-LINK-([a-f0-9]{40})\b!
+                my $key = $1;
+                my $repl = $_[0]->{$key};
+                if (defined $repl) {
+                        "<a\nhref=\"$pfx/$repl->[0]/\">$repl->[1]</a>";
+                } else {
+                        # false positive or somebody tried to mess with us
+                        $key;
+                }
+        !ge;
+}
+
 1;