[PATCH 27/30] wwwattach: avoid anonymous sub for msg_iter

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

We can pass arguments to msg_iter for msg_iter to pass
to our user-supplied callback, now.
---
 lib/PublicInbox/WwwAttach.pm | 49 ++++++++++++++++++++----------------
 1 file changed, 27 insertions(+), 22 deletions(-)

diff --git a/lib/PublicInbox/WwwAttach.pm b/lib/PublicInbox/WwwAttach.pm
index 2de56804..cda1c6c8 100644
--- a/lib/PublicInbox/WwwAttach.pm
+++ b/lib/PublicInbox/WwwAttach.pm
@@ -10,34 +10,39 @@ use Email::MIME::ContentType qw(parse_content_type);
 use PublicInbox::MIME;
 use PublicInbox::MsgIter;
 
+sub get_attach_i { # msg_iter callback
+	my ($part, $depth, @idx) = @{$_[0]};
+	my $res = $_[1];
+	return if join('.', @idx) ne $res->[3]; # $idx
+	$res->[0] = 200;
+	my $ct = $part->content_type;
+	$ct = parse_content_type($ct) if $ct;
+
+	# discrete == type, we remain Debian wheezy-compatible
+	if ($ct && (($ct->{discrete} || '') eq 'text')) {
+		# display all text as text/plain:
+		my $cset = $ct->{attributes}->{charset};
+		if ($cset && ($cset =~ /\A[a-zA-Z0-9_\-]+\z/)) {
+			$res->[1]->[1] .= qq(; charset=$cset);
+		}
+	} else { # TODO: allow user to configure safe types
+		$res->[1]->[1] = 'application/octet-stream';
+	}
+	$part = $part->body;
+	push @{$res->[1]}, 'Content-Length', bytes::length($part);
+	$res->[2]->[0] = $part;
+}
+
 # /$LISTNAME/$MESSAGE_ID/$IDX-$FILENAME
 sub get_attach ($$$) {
 	my ($ctx, $idx, $fn) = @_;
 	my $res = [ 404, [ 'Content-Type', 'text/plain' ], [ "Not found\n" ] ];
 	my $mime = $ctx->{-inbox}->msg_by_mid($ctx->{mid}) or return $res;
 	$mime = PublicInbox::MIME->new($mime);
-	msg_iter($mime, sub {
-		my ($part, $depth, @idx) = @{$_[0]};
-		return if join('.', @idx) ne $idx;
-		$res->[0] = 200;
-		my $ct = $part->content_type;
-		$ct = parse_content_type($ct) if $ct;
-
-		# discrete == type, we remain Debian wheezy-compatible
-		if ($ct && (($ct->{discrete} || '') eq 'text')) {
-			# display all text as text/plain:
-			my $cset = $ct->{attributes}->{charset};
-			if ($cset && ($cset =~ /\A[a-zA-Z0-9_\-]+\z/)) {
-				$res->[1]->[1] .= qq(; charset=$cset);
-			}
-		} else { # TODO: allow user to configure safe types
-			$res->[1]->[1] = 'application/octet-stream';
-		}
-		$part = $part->body;
-		push @{$res->[1]}, 'Content-Length', bytes::length($part);
-		$res->[2]->[0] = $part;
-	});
-	$res;
+	$res->[3] = $idx;
+	msg_iter($mime, \&get_attach_i, $res);
+	pop @$res; # cleanup before letting PSGI server see it
+	$res
 }
 
 1;