Re: [PATCH v4 2/2] format-patch: "--rfc=-(WIP)" appends to produce [PATCH (WIP)]

> On 23/04/2024 18:52, Junio C Hamano wrote:
>> In the previous step, the "--rfc" option of "format-patch" learned
>> to take an optional string value to prepend to the subject prefix,
>> so that --rfc=WIP can give "[WIP PATCH]".
>> 
>> There may be cases in which the extra string wants to come after the
>> subject prefix.  Extend the mechanism to allow "--rfc=-(WIP)" [*] to
>> signal that the extra string is to be appended instead of getting
>> prepended, resulting in "[PATCH (WIP)]".
>> 
>> In the documentation, discourage (ab)using "--rfc=-RFC" to say
>> "[PATCH RFC]" just to be different, when "[RFC PATCH]" is the norm.
>> 
>> [Footnote]
>> 
>>   * The syntax takes inspiration from Perl's open syntax that opens
>>     pipes "open fh, '|-', 'cmd'", where the dash signals "the other
>>     stuff comes here".
> 
> I'm not convinced this is a good idea as I'm not sure how adding "RFC"
> at the end of the subject prefix makes the world better than just
> having at the start of the prefix and I find using "-" to do that
> quite confusing.

>> Signed-off-by: Junio C Hamano <gitster@pobox.com>
>> ---
>>   Documentation/git-format-patch.txt | 6 ++++++
>>   builtin/log.c                      | 8 ++++++--
>>   t/t4014-format-patch.sh            | 9 +++++++++
>>   3 files changed, 21 insertions(+), 2 deletions(-)
>> 
>> diff --git a/Documentation/git-format-patch.txt 
>> b/Documentation/git-format-patch.txt
>> index e553810b1e..369af2c4a7 100644
>> --- a/Documentation/git-format-patch.txt
>> +++ b/Documentation/git-format-patch.txt
>> @@ -247,6 +247,12 @@ RFC means "Request For Comments"; use this when 
>> sending
>>   an experimental patch for discussion rather than application.
>>   "--rfc=WIP" may also be a useful way to indicate that a patch
>>   is not complete yet ("WIP" stands for "Work In Progress").
>> ++
>> +If the convention of the receiving community for a particular extra
>> +string is to have it _after_ the subject prefix, the string _<rfc>_
>> +can be prefixed with a dash ("`-`") to signal that the the rest of
>> +the _<rfc>_ string should be appended to the subject prefix instead,
>> +e.g., `--rfc='-(WIP)'` results in "PATCH (WIP)".
>>     -v <n>::
>>   --reroll-count=<n>::
>> diff --git a/builtin/log.c b/builtin/log.c
>> index 97ca885b33..4750e480e6 100644
>> --- a/builtin/log.c
>> +++ b/builtin/log.c
>> @@ -2065,8 +2065,12 @@ int cmd_format_patch(int argc, const char 
>> **argv, const char *prefix)
>>   	if (cover_from_description_arg)
>>   		cover_from_description_mode = 
>> parse_cover_from_description(cover_from_description_arg);
>>   -	if (rfc && rfc[0])
>> -		strbuf_insertf(&sprefix, 0, "%s ", rfc);
>> +	if (rfc && rfc[0]) {
>> +		if (rfc[0] == '-')
>> +			strbuf_addf(&sprefix, " %s", rfc + 1);
>> +		else
>> +			strbuf_insertf(&sprefix, 0, "%s ", rfc);
>> +	}
>>     	if (reroll_count) {
>>   		strbuf_addf(&sprefix, " v%s", reroll_count);
>> diff --git a/t/t4014-format-patch.sh b/t/t4014-format-patch.sh
>> index 645c4189f9..fcbde15b16 100755
>> --- a/t/t4014-format-patch.sh
>> +++ b/t/t4014-format-patch.sh
>> @@ -1394,6 +1394,15 @@ test_expect_success '--rfc=WIP and --rfc=' '
>>   	test_cmp expect-raw actual
>>   '
>>   +test_expect_success '--rfc=-(WIP) appends' '
>> +	cat >expect <<-\EOF &&
>> +	Subject: [PATCH (WIP) 1/1] header with . in it
>> +	EOF
>> +	git format-patch -n -1 --stdout --rfc="-(WIP)" >patch &&
>> +	grep "^Subject:" patch >actual &&
>> +	test_cmp expect actual
>> +'
>> +
>>   test_expect_success '--rfc does not overwrite prefix' '
>>   	cat >expect <<-\EOF &&
>>   	Subject: [RFC PATCH foobar 1/1] header with . in it