Subject: Re: [PATCH] git-send-email: add sendmailCommand option

From: Gregory Anders <[email-masked]>
Date: Wed, 12 May 2021 07:03:35 -0600

On Wed, 12 May 2021 13:19 +0900, Junio C Hamano wrote:
>Is this a totally unwarranted rewrapping of an unrelated part of the
>same document, or was there some words or phrases in this
>description of the envelope-sender option that needed to be adjusted
>for the introduction of sendmail-cmd option?

Yes it's just a rewrapping that I did while adding my new paragraph. The 
other reviewers pointed this out as well. My mistake, I will remove this 
from the next patch revision.

>> +--sendmail-cmd=<command>::
>> +	Specify a command to run to send the email. The command should
>> +	be compatible with `sendmail` as the arguments are passed
>> +	directly.  The command will be executed in the shell if
>> +	necessary.  Default is the value of `sendemail.sendmailCommand`.
>> +	If unspecified, and if --smtp-server is also unspecified,
>> +	git-send-email will search for `sendmail` in `/usr/sbin`,
>> +	`/usr/lib` and $PATH if such a program is available.

>OK, but doesn't this also need to support '-i'?

'The command should be compatible with `sendmail`' was meant to imply
this, though I can make this more explicit.

>> @@ -211,13 +221,14 @@ a password is obtained using 'git-credential'.
>>
>>  --smtp-server=<host>::
>>  	If set, specifies the outgoing SMTP server to use (e.g.
>> -	`smtp.example.com` or a raw IP address).  Alternatively it can
>> -	specify a full pathname of a sendmail-like program instead;
>> -	the program must support the `-i` option.  Default value can
>> -	be specified by the `sendemail.smtpServer` configuration
>> -	option; the built-in default is to search for `sendmail` in
>> -	`/usr/sbin`, `/usr/lib` and $PATH if such program is
>> -	available, falling back to `localhost` otherwise.
>> +	`smtp.example.com` or a raw IP address).  If unspecified, and if
>> +	`--sendmail-cmd` is also unspecified, the default is to search
>> +	for `sendmail` in `/usr/sbin`, `/usr/lib` and $PATH if such a
>> +	program is available, falling back to `localhost` otherwise.
>> +
>> +	For backward compatibility, this option can also specify a full
>> +	pathname of a sendmail-like program instead; the program must
>> +	support the `-i` option.  Prefer using `--sendmail-cmd` instead.

>Drop the last sentence, if we are not going to explain why.

I do think nudging users to use the "correct" option is valuable, so I 
will add some why text. Though I think adhering to the "--smtp-server 
should specify a host and --sendmail-cmd specifies a command" dichotomy 
is a good reason in and of itself.

>> @@ -1490,14 +1497,15 @@ sub send_message {
>>
>>  	unshift (@sendmail_parameters, @smtp_server_options);
>>
>> +	if (file_name_is_absolute($smtp_server)) {
>> +		# Preserved for backward compatibility
>> +		$sendmail_command ||= $smtp_server;
>> +	}
>
>Hmph, I wonder if this makes the intent more clear.
>
>	if (!defined $sendmail_command && file_name_is_absolute($smtp_server)) {
>		$sendmail_command = $smtp_server;
>	}
>
>That is, if the user gave us the command in newer form, we do not
>even have to bother checking if the server is given as an absolute
>pathname.

Yes I think you're right, I'll make this change.

>You seem to have replaced every smtp-server="$(pwd)/ mechanically
>with sendmai-cmd=\"$(pwd)/, but please make sure that we have at
>least one test left that passes an absolute path to --smtp-server to
>ensure that the old mechanism keeps working.  A bonus point for
>marking such a test that needs to be adjusted when the actual
>deprecation happens (i.e. we'd likely to detect the use of absolute
>path and throw a warning, so the test should notice the warning
>message).

Noted, I'll add a test for this case.

>Also you would want to tweak some of the --sendmail-cmd variants to
>use just the command name, with and without args, to ensure that (1)
>discovery on $PATH works, and (2) passing initial args works.

I did add two such tests:

diff --git a/t/t9001-send-email.sh b/t/t9001-send-email.sh
index 65b3035371..82a3efb987 100755
--- a/t/t9001-send-email.sh
+++ b/t/t9001-send-email.sh
@@ -2148,6 +2148,29 @@ test_expect_success $PREREQ 'leading and trailing whitespaces are removed' '
         test_cmp expected-list actual-list
  '

+test_expect_success $PREREQ 'test using relative path with sendmailCommand' '
+       clean_fake_sendmail &&
+       PATH="$(pwd):$PATH" \
+       git send-email \
+               --from="Example <[email-masked]>" \
+               --to=[email-masked] \
+               --sendmail-cmd="fake.sendmail" \
+               HEAD~2 &&
+       test_path_is_file commandline1 &&
+       test_path_is_file commandline2
+'
+
+test_expect_success $PREREQ 'test using shell with sendmailCommand' '
+       clean_fake_sendmail &&
+       git send-email \
+               --from="Example <[email-masked]>" \
+               --to=[email-masked] \
+               --sendmail-cmd="[ 1 -eq 1 ] && \"$(pwd)/fake.sendmail\"" \
+               HEAD~2 &&
+       test_path_is_file commandline1 &&
+       test_path_is_file commandline2
+'
+
  test_expect_success $PREREQ 'invoke hook' '
         mkdir -p .git/hooks &&

Granted, the second test tests for some generic shell expression, not 
passing arguments, but I think if the former works the latter ought to 
as well.

Thanks for your feedback.