Don't split on empty folded headers

lib/mail.rb

@@ -90,4 +90,5 @@ module Mail # :doc:
   require 'mail/mail'
 
   require 'monkeys/received_element'
+  require 'monkeys/message'
 end

lib/monkeys/message.rb

@@ -0,0 +1,9 @@
+module Mail
+  class Message
+    def parse_message
+      header_part, body_part = raw_source.lstrip.split(/#{CRLF}#{CRLF}|#{CRLF}#{WSP}{2,}#{CRLF}/m, 2)
+      self.header = header_part
+      self.body = body_part
+    end
+  end
+end

spec/fixtures/emails/mime_emails/sig_only_email.eml

@@ -7,6 +7,7 @@ Mime-Version: 1.0
 Content-Type: multipart/signed; boundary=Sig_2GIY2xfzqSADMmu9sKGJqWm;
  protocol="application/pgp-signature"; micalg=PGP-SHA1
 
+
 --Sig_2GIY2xfzqSADMmu9sKGJqWm
 Content-Type: text/plain; charset=US-ASCII
 Content-Transfer-Encoding: quoted-printable

spec/monkeys/message_spec.rb

@@ -0,0 +1,26 @@
+require 'spec_helper'
+
+describe Mail::Message do
+  describe 'splitting' do
+    it "doesn't split the message at an empty folded header" do
+      message = Mail::Message.new("To: foo\r\n \r\nFrom: bar\r\n\r\nbody\r\n")
+      message.decoded.should == 'body'
+    end
+
+    # Borrowed from
+    # https://github.com/mikel/mail/commit/a2a45597bce66ebe788cedaaab848a37bd04b25a
+    it 'splits only once if there are "\r\n\r\n"s in the body' do
+      message = Mail::Message.new("To: Example <example@cirw.in>\r\n\r\nHello\r\n\r\nthere\r\n")
+      message.decoded.should == "Hello\n\nthere"
+    end
+
+    # Note: Non RFC Conformant
+    # http://tools.ietf.org/html/rfc2822#section-3.5
+    # Added to minimize behaviour differences with 2-4 stable, and to not break
+    # rspec ./spec/mail/message_spec.rb:274 # Mail::Message accepting a plain text string email should give allow for whitespace on the gap line between header and body
+    it 'allows 2 or more whitespaces on the gap line between header and body' do
+      message = Mail::Message.new("To: foo\r\n  \r\nbody\r\n")
+      message.decoded.should == 'body'
+    end
+  end
+end