Quoted-printable encoding inserts unnecessary line breaks
K-9 Mail created a message that contained unnecessary line breaks in the encoded message body.
(v5.111)

```
[...]
Content-Type: text/plain;
 charset=utf-8
Content-Transfer-Encoding: quoted-printable
MIME-Version: 1.0

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA512

[...]
-----BEGIN PGP SIGNATURE-----

iQI0BAEBCgAeFxxCZXJuZCA8dGVzdEBja2V0dGkuZGU=
+BQJX1LDSAAoJEG2bO4IG
m2wDJ6YQAIc3oA5JPv122U0IdBWN0c0CPr0bm6e+Z7dlAOCmNdhO/=
WxhMTEI1u4v
AL9AySWQIeek3tWZJSgSfhULXCC1ZUU2tWA/1cpf9PMpdXknJvi8y34osV+0SnU=
/
LhIkMPUK2wGUYmDUvBL2g9Zbx4giknta+2/IbaGMljRHQuDV1XpHEVDKzRE73VID
xn7F7CSI=
xkQGPI6mNOuM70BsaVyCwrTRiSW4rnwe2CgLf+RVSePCnveTjxC6xZyC
Q7z1LBKGNEvw0PRKjM=
1IbNeFSJ3y73RBS4y1cDYECWxKPjDJ5PR9x2QzcTdqKbXp
pVXJEv/8SzurR99V1OvlTS3s2tdS=
fSLpd9uP1hqxK71Dek5fcMUHQqgsIz2mmiEa
dExWc9dItBjgH9dPyBXn9m/G5UnF1E8FbqlS7J=
swgfiW0KNAkYEsFyvjp7q7W6TK
qkYnxJCENCG4Hf+lofDEzHth/uu23Z7cHhjkzZDet0dMGpA+=
B1jH9ZVu4aEoWLGQ
VJ3Lfjqy4ZysAmziR8iKcg3V/q0vmL+zC+3s9U+UaXPbpI2JD/hr89WIkG=
zVnNpG
8hInOIgLOJhui5PFEB7XNdpBJj+O2NYigV76Fvhb4boyCt7VdhRe01C7cohusPHB
/TO=
wbqG+0w+z6eL8tyxZ2HVWFyfgHyarnwGquIxYjxE5OzfS+LN4
=3DS8iC
-----END PGP SIGN=
ATURE-----
```

diff --git a/k9mail/src/main/java/com/fsck/k9/message/PgpMessageBuilder.java b/k9mail/src/main/java/com/fsck/k9/message/PgpMessageBuilder.java
index b0c5d10b9..11638b6e0 100644
--- a/k9mail/src/main/java/com/fsck/k9/message/PgpMessageBuilder.java
+++ b/k9mail/src/main/java/com/fsck/k9/message/PgpMessageBuilder.java
@@ -20,6 +20,7 @@ import com.fsck.k9.mail.Body;
 import com.fsck.k9.mail.BodyPart;
 import com.fsck.k9.mail.BoundaryGenerator;
 import com.fsck.k9.mail.MessagingException;
+import com.fsck.k9.mail.filter.EOLConvertingOutputStream;
 import com.fsck.k9.mail.internet.BinaryTempFileBody;
 import com.fsck.k9.mail.internet.MessageIdGenerator;
 import com.fsck.k9.mail.internet.MimeBodyPart;
@@ -193,6 +194,9 @@ public class PgpMessageBuilder extends MessageBuilder {
                 pgpResultTempBody = new BinaryTempFileBody(
                         capturedOutputPartIs7Bit ? MimeUtil.ENC_7BIT : MimeUtil.ENC_8BIT);
                 outputStream = pgpResultTempBody.getOutputStream();
+                // OpenKeychain/BouncyCastle at this point use the system newline for formatting, which is LF on android.
+                // we need this to be CRLF, so we convert the data after receiving.
+                outputStream = new EOLConvertingOutputStream(outputStream);
             } catch (IOException e) {
                 throw new MessagingException("could not allocate temp file for storage!", e);
             }
['k9mail/src/main/java/com/fsck/k9/message/PgpMessageBuilder.java']