From a2ad0bd9b5949542a685e4ee833252b6184961d9 Mon Sep 17 00:00:00 2001
From: Thomas Hochstein <thh@inter.net>
Date: Sun, 13 Oct 2019 13:15:27 +0200
Subject: [PATCH] Fix mangling of auto-generated mails.

s9y will encode the body of its auto-generated
mails as quoted-printable when imap_8bit() is
available. imap_8bit() will use "\r\n" as
linebreaks as mandated for SMTP transfer.
The result will be transmitted via PHP's
mail() function, using direct SMTP on
Windows and piping it to a MTA on Unix.

Most MTAs will cope just fine with those
linebreaks, while qmail will not; it will
replace all "\n" linebreaks with "\r\n",
so we get "\r\r\n" in our case. We can't
"fix" qmail (as its maintainer, if there
even is one, does not consider this
behaviour wrong), but we can replace the
line endings we get from imap_8bit().

The fix does work with qmail and Exim and
should work with sendmail and Postfix and
other MTAs, too. It may break sending
mail on Windows (i.e. lose all linebreaks),
but I think that's acceptable, as we'll
have more qmail installation than Windows
servers out there.

A workaround could be to set
serendipity['forceBase64']=true in
serendipity_config_local.inc.php, but I'd
prefer this fix.

Fixes #644.

Backported from master branch.

Signed-off-by: Thomas Hochstein <thh@inter.net>
---
 docs/NEWS                 | 5 +++++
 include/functions.inc.php | 2 +-
 2 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/docs/NEWS b/docs/NEWS
index 8a2b6a4b5..f0930a89e 100644
--- a/docs/NEWS
+++ b/docs/NEWS
@@ -1,6 +1,11 @@
 Version 2.3.2-beta1 ()
 ------------------------------------------------------------------------
 
+   * Fix: Auto-generated mails submitted to qmail as MTA will get
+          mangled if encoded to quoted-printable due to qmail
+          changing "\r\n" linebreaks to "\r\r\n". Submit just "\n"
+          as linebreaks; other MTAs should cope with that.
+
    * fix: Rotating an image did not rotate all responsive thumbnails
    
    * fix: The wysiwyg editor stripped the figcaption element used
diff --git a/include/functions.inc.php b/include/functions.inc.php
index eb72a6076..545484e79 100644
--- a/include/functions.inc.php
+++ b/include/functions.inc.php
@@ -538,7 +538,7 @@ function serendipity_sendMail($to, $subject, $message, $fromMail, $headers = NUL
         if (LANG_CHARSET == 'UTF-8') {
             if (function_exists('imap_8bit') && !$serendipity['forceBase64']) {
                 $maildata['headers'][] = 'Content-Transfer-Encoding: quoted-printable';
-                $maildata['message']   = imap_8bit($maildata['message']);
+                $maildata['message']   = str_replace("\r\n","\n",imap_8bit($maildata['message']));
             } else {
                 $maildata['headers'][] = 'Content-Transfer-Encoding: base64';
                 $maildata['message']   = chunk_split(base64_encode($maildata['message']));