From 0beff4cdb8f51e1a53911a95b70d3a12823713aa Mon Sep 17 00:00:00 2001
From: Vincent Breitmoser <look@my.amazin.horse>
Date: Tue, 6 Dec 2016 23:27:13 +0100
Subject: [PATCH] use message/rfc822 as default content type for
 multipart/digest subparts

---
 .../java/com/fsck/k9/mail/internet/MimeBodyPart.java   | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/k9mail-library/src/main/java/com/fsck/k9/mail/internet/MimeBodyPart.java b/k9mail-library/src/main/java/com/fsck/k9/mail/internet/MimeBodyPart.java
index 5a784cb14..f5e5725ec 100644
--- a/k9mail-library/src/main/java/com/fsck/k9/mail/internet/MimeBodyPart.java
+++ b/k9mail-library/src/main/java/com/fsck/k9/mail/internet/MimeBodyPart.java
@@ -4,6 +4,7 @@ package com.fsck.k9.mail.internet;
 import com.fsck.k9.mail.Body;
 import com.fsck.k9.mail.BodyPart;
 import com.fsck.k9.mail.MessagingException;
+import com.fsck.k9.mail.Multipart;
 
 import java.io.BufferedWriter;
 import java.io.IOException;
@@ -93,7 +94,14 @@ public class MimeBodyPart extends BodyPart {
     @Override
     public String getContentType() {
         String contentType = getFirstHeader(MimeHeader.HEADER_CONTENT_TYPE);
-        return (contentType == null) ? "text/plain" : MimeUtility.unfoldAndDecode(contentType);
+        if (contentType != null) {
+            return MimeUtility.unfoldAndDecode(contentType);
+        }
+        Multipart parent = getParent();
+        if (parent != null && "multipart/digest".equals(parent.getMimeType())) {
+            return "message/rfc822";
+        }
+        return "text/plain";
     }
 
     @Override