Omit \r\r\n

[ionum]

Check if endline is already \r\n

[bruceg]

This is simple enough, but I have a couple of questions:

1. Would it make sense for it to be a while instead of an if to effect stripping all trailing \r?
2. It would be good to test this behavior. Have you taken a look at doing that?

[ionum]

1. I don't think so. Mail-delivering-programms use \r\n or \n as line terminators. * getline splits on \n so only one \r remains at the end of the line if the Mail-delivering-programm uses \r\n
2. I wrote that patch because my mails got crippled. I'm testing my patch since Jun 2021 :-). No problems so far.

*RFC 2821: SMTP commands and, unless altered by a service extension, message
data, are transmitted in "lines". Lines consist of zero or more data
characters terminated by the sequence ASCII character "CR" (hex value
0D) followed immediately by ASCII character "LF" (hex value 0A).
This termination sequence is denoted as in this document.
Conforming implementations MUST NOT recognize or generate any other
character or character sequence as a line terminator. Limits MAY be
imposed on line lengths by servers (see section 4.5.3).

In addition, the appearance of "bare" "CR" or "LF" characters in text
(i.e., either without the other) has a long history of causing
problems in mail implementations and applications that use the mail
system as a tool. SMTP client implementations MUST NOT transmit
these characters except when they are intended as line terminators
and then MUST, as indicated above, transmit them only as a
sequence.

[maxpunktezahl]

Just an additional hint. I anybody wan't to use the (great!) nullmailer with s/mime encoded mails like me, ionums patch is absolutely essential. All attempts to sign (end encrypt) mails with 'openssl smime' will fail without the patch! See https://stackoverflow.com/questions/66228622/how-to-use-openssl-to-sign-an-email-message-and-curl-to-send-it
The pached smtp lib worked instantly with s/mime.

[bmork]

Please merge this. It fixes errors like this one:

2024-10-02T12:39:11.650699+02:00 miraculix nullmailer-send[1506356]: smtp: Failed: 421 4.5.0 Bare carriage return (CR) not allowed

which showed up regularily after my sendmail based smart relay got a fix for CVE-2023-51765. Typically caused by a cron job printing a message ending in \r.

I believe the problem can be reproduced by simply doing:

echo -e "To: recipient@example.com\n\nFoo\r"|nullmailer-inject