lib/PublicInbox/MsgIter.pm       | 5 +++--
 lib/PublicInbox/SolverGit.pm     | 5 ++---
 lib/PublicInbox/View.pm          | 6 +++---
 lib/PublicInbox/WwwAtomStream.pm | 4 ++--
 lib/PublicInbox/WwwAttach.pm     | 2 +-

diff --git a/lib/PublicInbox/MsgIter.pm b/lib/PublicInbox/MsgIter.pm
index cdd78b39b2afaf75dea36062c40354afab2c1e18..f238954bcdd5b7a04c8f631c8308d067f3146945 100644
--- a/lib/PublicInbox/MsgIter.pm
+++ b/lib/PublicInbox/MsgIter.pm
@@ -12,10 +12,11 @@
 # Like Email::MIME::walk_parts, but this is:
 # * non-recursive
 # * passes depth and indices to the iterator callback
-sub msg_iter ($$;$) {
-	my ($mime, $cb, $cb_arg) = @_;
+sub msg_iter ($$;$$) {
+	my ($mime, $cb, $cb_arg, $do_undef) = @_;
 	my @parts = $mime->subparts;
 	if (@parts) {
+		$mime = $_[0] = undef if $do_undef; # saves some memory
 		my $i = 0;
 		@parts = map { [ $_, 1, ++$i ] } @parts;
 		while (my $p = shift @parts) {
diff --git a/lib/PublicInbox/SolverGit.pm b/lib/PublicInbox/SolverGit.pm
index 8629f0dafeb4216b41ac2c0951c866c8e76c2dcf..b48e8ac429e8676687ad97919a1bcfb373b17f7e 100644
--- a/lib/PublicInbox/SolverGit.pm
+++ b/lib/PublicInbox/SolverGit.pm
@@ -233,9 +233,8 @@
 	my $diffs = [];
 	foreach my $smsg (@$msgs) {
 		$ibx->smsg_mime($smsg) or next;
-		my $mime = delete $smsg->{mime};
-		msg_iter($mime, \&extract_diff,
-				[$self, $diffs, $pre, $post, $ibx, $smsg]);
+		msg_iter(delete $smsg->{mime}, \&extract_diff,
+				[$self, $diffs, $pre, $post, $ibx, $smsg], 1);
 	}
 	@$diffs ? $diffs : undef;
 }
diff --git a/lib/PublicInbox/View.pm b/lib/PublicInbox/View.pm
index 405da2a930a9fe104983cfec75ea20ea45d8bb72..d88b34da431f0975282993f885a6ab0ee44fa443 100644
--- a/lib/PublicInbox/View.pm
+++ b/lib/PublicInbox/View.pm
@@ -275,7 +275,7 @@
 	# scan through all parts, looking for displayable text
 	$ctx->{mhref} = $mhref;
 	$ctx->{rv} = \$rv;
-	msg_iter($mime, \&add_text_body, $ctx);
+	msg_iter($mime, \&add_text_body, $ctx, 1);
 	delete $ctx->{rv};
 
 	# add the footer
@@ -506,12 +506,12 @@ 	$$skel;
 }
 
 sub multipart_text_as_html {
-	my ($mime, $mhref, $ctx) = @_;
+	my (undef, $mhref, $ctx) = @_; # $mime = $_[0]
 	$ctx->{mhref} = $mhref;
 	$ctx->{rv} = \(my $rv = '');
 
 	# scan through all parts, looking for displayable text
-	msg_iter($mime, \&add_text_body, $ctx);
+	msg_iter($_[0], \&add_text_body, $ctx, 1);
 	${delete $ctx->{rv}};
 }
 
diff --git a/lib/PublicInbox/WwwAtomStream.pm b/lib/PublicInbox/WwwAtomStream.pm
index 9430dd97679eed5049d65de63bc96129b8159b27..9ec1383dada276b101a35df7ea3809692609567e 100644
--- a/lib/PublicInbox/WwwAtomStream.pm
+++ b/lib/PublicInbox/WwwAtomStream.pm
@@ -101,9 +101,9 @@ # returns undef or string
 sub feed_entry {
 	my ($self, $smsg) = @_;
 	my $ctx = $self->{ctx};
-	my $mime = $smsg->{mime};
+	my $mid = $smsg->mid; # may extract Message-ID from {mime}
+	my $mime = delete $smsg->{mime};
 	my $hdr = $mime->header_obj;
-	my $mid = $smsg->mid;
 	my $irt = PublicInbox::View::in_reply_to($hdr);
 	my $uuid = to_uuid($mid);
 	my $base = $ctx->{feed_base_url};
diff --git a/lib/PublicInbox/WwwAttach.pm b/lib/PublicInbox/WwwAttach.pm
index cda1c6c8db3a0745e8ad28a1cffaad05e10de6cf..92f47e4913ae7b006da939e612969f3fdf1ad1a4 100644
--- a/lib/PublicInbox/WwwAttach.pm
+++ b/lib/PublicInbox/WwwAttach.pm
@@ -40,7 +40,7 @@ 	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);
 	$res->[3] = $idx;
-	msg_iter($mime, \&get_attach_i, $res);
+	msg_iter($mime, \&get_attach_i, $res, 1);
 	pop @$res; # cleanup before letting PSGI server see it
 	$res
 }