handle "multipart/mixed" messages which are not multipart

I've found two examples on https://lore.kernel.org/lkml/
where the messages declared themselves to be "multipart/mixed"
but were actually plain text:

	<87llgalspt.fsf@free.fr>
	<200308111450.h7BEoOu20077@mail.osdl.org>

With the mboxrd downloaded, mutt is able to view them without
difficulty.

Note: this change would require reindexing of Xapian to pick up
the changes.  But it's only two ancient messages, the first was
resent by the original sender and the second is too old to be
relevant.

1 files changed, 1 insertions, 8 deletions

diff --git a/lib/PublicInbox/ContentId.pm b/lib/PublicInbox/ContentId.pm
index b1d27eb8..dd3155be 100644
--- a/lib/PublicInbox/ContentId.pm
+++ b/lib/PublicInbox/ContentId.pm
@@ -75,14 +75,7 @@ sub content_digest ($) {
                 }
                 $dig->add("b\0");
                 my $ct = $part->content_type || 'text/plain';
-                my $s = eval { $part->body_str };
-                if ($@ && $ct =~ m!\btext/plain\b!i) {
-                        # Try to assume UTF-8 because Alpine
-                        # seems to do wacky things and set
-                        # charset=X-UNKNOWN
-                        $part->charset_set('UTF-8');
-                        $s = eval { $part->body_str };
-                }
+                my ($s, undef) = msg_part_text($part, $ct);
                 if (defined $s) {
                         $s =~ s/\r\n/\n/gs;
                         $s =~ s/\s*\z//s;