From: Eric Wong <e@yhbt.net>
Date: Mon, 25 May 2020 08:21:37 +0000 (+0000)
Subject: view: do not offer links to 0-byte multipart attachments
X-Git-Tag: v1.6.0~488
X-Git-Url: http://www.git.stargrave.org/?a=commitdiff_plain;h=8604ccc806997eadf78e2b6352b4daa0287b8bb0;p=public-inbox.git

view: do not offer links to 0-byte multipart attachments

Offering links to download 0-byte files is useless.  We could
waste memory by preserving $eml->{bdy} during iteration, but
offering attachments of type "multipart" is not very useful,
as users are usually interested in decoded attachments or
the entire raw message.

Fixes: e60231148eb604a3 ("descend into message/(rfc822|news|global) parts")
---

diff --git a/lib/PublicInbox/View.pm b/lib/PublicInbox/View.pm
index 93a5b329..a05ac414 100644
--- a/lib/PublicInbox/View.pm
+++ b/lib/PublicInbox/View.pm
@@ -499,6 +499,11 @@ sub submsg_hdr ($$) {
 sub attach_link ($$$$;$) {
 	my ($ctx, $ct, $p, $fn, $err) = @_;
 	my ($part, $depth, $idx) = @$p;
+
+	# Eml iteration clobbers multipart ->{bdy}, so do not offer
+	# downloads for 0-byte multipart attachments
+	return unless $part->{bdy};
+
 	my $nl = $idx eq '1' ? '' : "\n"; # like join("\n", ...)
 	my $size = bytes::length($part->body);
 
diff --git a/t/psgi_attach.t b/t/psgi_attach.t
index c6f8072f..9a734f81 100644
--- a/t/psgi_attach.t
+++ b/t/psgi_attach.t
@@ -73,6 +73,8 @@ $im->init_bare;
 		my $mid = '20200418222508.GA13918@dcvr';
 		my $irt = '20200418222020.GA2745@dcvr';
 		$res = $cb->(GET("/test/$mid/"));
+		unlike($res->content, qr! multipart/mixed, Size: 0 bytes!,
+			'0-byte download not offered');
 		like($res->content, qr/\bhref="2-embed2x\.eml"/s,
 			'href to message/rfc822 attachment visible');
 		like($res->content, qr/\bhref="2\.1\.2-test\.eml"/s,