Check if in text/plain is content - if not, use text/html.

app/models/channel/email_parser.rb

@@ -134,9 +134,10 @@ class Channel::EmailParser
         if !data[:body].valid_encoding?
           data[:body] = data[:body].encode('utf-8', 'binary', invalid: :replace, undef: :replace, replace: '?')
         end
+      end
 
       # html attachment/body may exists and will be converted to text
-      else
+      if !mail.text_part || !data[:body] || data[:body] == ''
         filename = '-no name-'
         if mail.html_part && mail.html_part.body
           filename = 'message.html'

test/fixtures/mail34.box

@@ -0,0 +1,29 @@
+From: "Bay" <memberbay+12345@members.somewhat>
+Subject: strange email with empty text/plain
+To: bay@example.com
+Date: 11 Nov 2015 12:07:51 +0000
+Priority: normal
+X-Priority: 3 (Normal)
+Importance: normal
+X-David-SYM: 0
+X-David-Flags: 0
+Message-ID: <7ca10659-214c-4bd0-8438-b935a01c7601@stange>
+MIME-Version: 1.0
+Content-Type: multipart/alternative; boundary="----_=_NextPart_000_06409CFC.56433DA7"
+
+This message is in MIME format. Since your mail reader does not understand
+this format, some or all of this message may not be legible.
+
+------_=_NextPart_000_06409CFC.56433DA7
+Content-Type: text/plain; charset=iso-8859-1
+Content-Transfer-Encoding: quoted-printable
+
+
+
+------_=_NextPart_000_06409CFC.56433DA7
+Content-Type: text/html; charset=utf-8
+Content-Transfer-Encoding: quoted-printable
+
+<b>some html text</b>
+
+------_=_NextPart_000_06409CFC.56433DA7

test/unit/email_parser_test.rb

@@ -308,7 +308,7 @@ Hof
       # spam email
       {
         data: IO.read('test/fixtures/mail15.box'),
-        body_md5: 'd41d8cd98f00b204e9800998ecf8427e',
+        body_md5: '5872ddcdfdf6bfe40f36cd0408fca667',
         attachments: [
           # :preferences=>{"Message-ID"=>"<temp@test>", "Content-Type"=>"application/octet-stream; name=\"\xBC\xA8\xD0\xA7\xB9\xDC\xC0\xED,\xBE\xBF\xBE\xB9\xCB\xAD\xB4\xED\xC1\xCB.xls\"", "Mime-Type"=>"application/octet-stream", "Charset"=>"UTF-8"}}
           # mutt c1abb5fb77a9d2ab2017749a7987c074
@@ -466,14 +466,14 @@ Freemont and pulling out several minutes.
       },
       {
         data: IO.read('test/fixtures/mail24.box'),
-        body_md5: 'd41d8cd98f00b204e9800998ecf8427e',
+        body_md5: '5872ddcdfdf6bfe40f36cd0408fca667',
         params: {
           from: 'oracle@IG0-1-DB01.example.com',
           from_email: 'oracle@IG0-1-DB01.example.com',
           from_display_name: '',
           subject: 'Regelsets im Test-Status gefunden: 1',
           to: 'support@example.com',
-          body: '',
+          body: 'no visible content',
         },
         attachments: [
           {
@@ -672,9 +672,24 @@ Weil wir die Echtheit oder Vollständigkeit der in dieserNachricht enthaltenen I
           to: 'info@znuny.inc',
         },
       },
+      {
+        data: IO.read('test/fixtures/mail34.box'),
+        body_md5: 'b6e46176404ec81b3ab412fe71dff0f0',
+        params: {
+          from: 'Bay <memberbay+12345@members.somewhat>',
+          from_email: 'memberbay+12345@members.somewhat',
+          from_display_name: 'Bay',
+          subject: 'strange email with empty text/plain',
+          to: 'bay@example.com',
+          body: 'some html text',
+        },
+      },
     ]
 
+    count = 0
     files.each { |file|
+      count += 1
+      #p "Count: #{count}"
       parser = Channel::EmailParser.new
       data = parser.parse( file[:data] )