Multi-part messages without content-type in subparts are misparsed

[wolfsage]

A multi-part message that has subparts without an explicit content-type (or any other headers) is misparsed. For example:

em.pl:

#!/usr/bin/perl

use strict;
use warnings;

use Email::MIME;

open(my $fh, '<', shift) or die "Failed: $!\n";
local $/;
my $data = <$fh>;
close $fh;

my $em = Email::MIME->new($data);

my @parts = $em->subparts;

print "Part one (with content-type): \n" . $parts[0]->body . "\n";

print "Part two (without content-type): \n" . $parts[1]->body . "\n";

When run against this file:

ex.email

From: Test <test@test.com>
To: Test <test@test.com>
Subject: Test
Content-Type: multipart/alternative; boundary=90e6ba6e8d06f1723604fc1b809a

--90e6ba6e8d06f1723604fc1b809a
Content-Type: text/plain; charset=UTF-8

Paragraph 1

Paragraph 2

--90e6ba6e8d06f1723604fc1b809a

Paragraph 1

Paragraph 2

--90e6ba6e8d06f1723604fc1b809a--

prints out:

./em.pl ex.email
Use of uninitialized value in lc at /usr/local/share/perl/5.14.2/Email/Simple/Header.pm line 125.
Use of uninitialized value in lc at /usr/local/share/perl/5.14.2/Email/Simple/Header.pm line 125.
Part one (with content-type): 
Paragraph 1

Paragraph 2
Use of uninitialized value in lc at /usr/local/share/perl/5.14.2/Email/Simple/Header.pm line 125.
Part two (without content-type): 
Paragraph 2

Note that the warnings all come from the second subpart; if a content-type is set in it as in the first subpart, the warnings go away and it works as expected.

I suspect the first paragraph in the second subpart is being parsed as a header.

[eengstrom]

I can confirm this with a fresh CPAN install of Email::MIME (v1.937) and a simpler test case:

#!/usr/bin/env perl
use Email::MIME;

$/ = undef;
my $text = <DATA>;
#print $text;
my $mail = Email::MIME->new($text);

__DATA__
From: someone@somewhere.com
To: nobody@nowhere.com
Subject: failure notice
Content-Type: multipart/mixed; boundary="1446656133441981"

--1446656133441981

content elided

--1446656133441981--

Note that there is only one subpart and it has no content-type. I note that the original report is relatively old (2014). Anyone still interested besides me?

[rjbs]

I am still interested, but I have not been bitten and so haven't spent the time to try to make a patch.

[eengstrom]

@rjbs - does the test case fail for you? If yes, then perhaps you can point me in a direction to help contribute a patch, but the tricky part seems to be that it's actually that we are tickling a bug in the Email::Simple module, but should protect against it here.

[wolfsage]

Possible fix attached