Subject: Re: [PATCH v8 1/6] interpret-trailers: factor trailer rewriting

From: Phillip Wood <[email-masked]>
Date: Mon, 9 Mar 2026 10:36:53 +0000

On 06/03/2026 21:04, Junio C Hamano wrote:
> Phillip Wood <[email-masked]> writes:
> 
>> From: Li Chen <[email-masked]>
>>
>> Extract the trailer rewriting logic into a helper that appends to an
>> output strbuf.
>>
>> Update interpret_trailers() to handle file I/O only: read input once,
>> call the helper, and write the buffered result.
>>
>> This separation makes it easier to move the helper into trailer.c in the
>> next commit.
>>
>> Signed-off-by: Phillip Wood <[email-masked]>
>> Signed-off-by: Li Chen <[email-masked]>
>> ---
> 
> If "Li wrote it and signed it off, Phillip is relaying" is what is
> happening, the sign-offs are in reverse order.  If "Li incorporated
> what Phillip wrote earlier in his larger work", then the sign-offs
> may be fine, but it would be necessary to hint that that is what
> happened in the proposed log message.  I cannot quite tell which is
> the case.

It's the latter, I posted a diff[1] and Li based this patch on that diff

Thanks

Phillip

[1] 
https://lore.kernel.org/git/[email-masked]/
>>   builtin/interpret-trailers.c | 57 ++++++++++++++++++++----------------
>>   1 file changed, 32 insertions(+), 25 deletions(-)
>>
>> diff --git a/builtin/interpret-trailers.c b/builtin/interpret-trailers.c
>> index 41b0750e5af..69f9d67ec0e 100644
>> --- a/builtin/interpret-trailers.c
>> +++ b/builtin/interpret-trailers.c
>> @@ -136,32 +136,21 @@ static void read_input_file(struct strbuf *sb, const char *file)
>>   	strbuf_complete_line(sb);
>>   }
>>   
>> -static void interpret_trailers(const struct process_trailer_options *opts,
>> -			       struct list_head *new_trailer_head,
>> -			       const char *file)
>> +static void process_trailers(const struct process_trailer_options *opts,
>> +			     struct list_head *new_trailer_head,
>> +			     struct strbuf *input, struct strbuf *out)
>>   {
>>   	LIST_HEAD(head);
>> -	struct strbuf sb = STRBUF_INIT;
>> -	struct strbuf trailer_block_sb = STRBUF_INIT;
>>   	struct trailer_block *trailer_block;
>> -	FILE *outfile = stdout;
>> -
>> -	trailer_config_init();
>> -
>> -	read_input_file(&sb, file);
>> -
>> -	if (opts->in_place)
>> -		outfile = create_in_place_tempfile(file);
>> -
>> -	trailer_block = parse_trailers(opts, sb.buf, &head);
>> +
>> +	trailer_block = parse_trailers(opts, input->buf, &head);
>>   
>>   	/* Print the lines before the trailer block */
>>   	if (!opts->only_trailers)
>> -		fwrite(sb.buf, 1, trailer_block_start(trailer_block), outfile);
>> +		strbuf_add(out, input->buf, trailer_block_start(trailer_block));
>>   
>>   	if (!opts->only_trailers && !blank_line_before_trailer_block(trailer_block))
>> -		fprintf(outfile, "\n");
>> -
>> +		strbuf_addch(out, '\n');
>>   
>>   	if (!opts->only_input) {
>>   		LIST_HEAD(config_head);
>> @@ -173,22 +162,40 @@ static void interpret_trailers(const struct process_trailer_options *opts,
>>   	}
>>   
>>   	/* Print trailer block. */
>> -	format_trailers(opts, &head, &trailer_block_sb);
>> +	format_trailers(opts, &head, out);
>>   	free_trailers(&head);
>> -	fwrite(trailer_block_sb.buf, 1, trailer_block_sb.len, outfile);
>> -	strbuf_release(&trailer_block_sb);
>>   
>>   	/* Print the lines after the trailer block as is. */
>>   	if (!opts->only_trailers)
>> -		fwrite(sb.buf + trailer_block_end(trailer_block), 1,
>> -		       sb.len - trailer_block_end(trailer_block), outfile);
>> +		strbuf_add(out, input->buf + trailer_block_end(trailer_block),
>> +			   input->len - trailer_block_end(trailer_block));
>>   	trailer_block_release(trailer_block);
>> -
>> +}
>> +
>> +static void interpret_trailers(const struct process_trailer_options *opts,
>> +			       struct list_head *new_trailer_head,
>> +			       const char *file)
>> +{
>> +	struct strbuf input = STRBUF_INIT;
>> +	struct strbuf out = STRBUF_INIT;
>> +	FILE *outfile = stdout;
>> +
>> +	trailer_config_init();
>> +
>> +	read_input_file(&input, file);
>> +
>> +	if (opts->in_place)
>> +		outfile = create_in_place_tempfile(file);
>> +
>> +	process_trailers(opts, new_trailer_head, &input, &out);
>> +
>> +	strbuf_write(&out, outfile);
>>   	if (opts->in_place)
>>   		if (rename_tempfile(&trailers_tempfile, file))
>>   			die_errno(_("could not rename temporary file to %s"), file);
>>   
>> -	strbuf_release(&sb);
>> +	strbuf_release(&input);
>> +	strbuf_release(&out);
>>   }
>>   
>>   int cmd_interpret_trailers(int argc,