Re: [PATCH 1/1] replay: add --revert option to reverse commit changes

[Junio C Hamano <gitster@pobox.com>]

Junio C Hamano <gitster@pobox.com> writes:

> In do_pick_commit() where TODO_REVERT command is handled, we find a
> code block that is almost identical to what this patch adds to the
> new helper function; it should be rewritten to call the new helper
> function or perhaps a shared helper function is introduced and
> called from there and also from the sequencer_format_revert_header()
> function, if there is still some impedance mismatch.  If such a
> refactoring is done as a separate preliminary patch in a N-patch
> series, the resulting patch series may be easier to follow (and
> there may be other opportunities to reuse existing code more).
> ...
>> diff --git a/sequencer.c b/sequencer.c
>> index 5476d39ba9..e6d82c8368 100644
>> --- a/sequencer.c
>> +++ b/sequencer.c
>> @@ -5572,6 +5572,29 @@ int sequencer_pick_revisions(struct repository *r,
>>  	return res;
>>  }
>>  
>> +void sequencer_format_revert_header(struct strbuf *out, const char *orig_subject)
>> +{
>> +	const char *revert_subject;
>> +
>> +	if (skip_prefix(orig_subject, "Revert \"", &revert_subject) &&
>> +	    /*
>> +	     * We don't touch pre-existing repeated reverts, because
>> +	     * theoretically these can be nested arbitrarily deeply,
>> +	     * thus requiring excessive complexity to deal with.
>> +	     */
>> +	    !starts_with(revert_subject, "Revert \"")) {
>> +		strbuf_addstr(out, "Reapply \"");
>> +		strbuf_addstr(out, revert_subject);
>> +		strbuf_addch(out, '\n');
>> +	} else {
>> +		strbuf_addstr(out, "Revert \"");
>> +		strbuf_addstr(out, orig_subject);
>> +		strbuf_addstr(out, "\"\n");
>> +	}
>> +
>> +	strbuf_addstr(out, "\nThis reverts commit ");
>> +}
>> +
>
> Dedup with do_pick_commit() where this was taken from.  Possibly in
> a separte patch before the main one.

Forgot to attach this at the end.  What I meant was that something
along this line may be a good starting point.

 sequencer.c | 14 +-------------
 1 file changed, 1 insertion(+), 13 deletions(-)

diff --git c/sequencer.c w/sequencer.c
index e6d82c8368..29909952d4 100644
--- c/sequencer.c
+++ w/sequencer.c
@@ -2365,20 +2365,8 @@ static int do_pick_commit(struct repository *r,
 		if (opts->commit_use_reference) {
 			strbuf_commented_addf(&ctx->message, comment_line_str,
 				"*** SAY WHY WE ARE REVERTING ON THE TITLE LINE ***");
-		} else if (skip_prefix(msg.subject, "Revert \"", &orig_subject) &&
-			   /*
-			    * We don't touch pre-existing repeated reverts, because
-			    * theoretically these can be nested arbitrarily deeply,
-			    * thus requiring excessive complexity to deal with.
-			    */
-			   !starts_with(orig_subject, "Revert \"")) {
-			strbuf_addstr(&ctx->message, "Reapply \"");
-			strbuf_addstr(&ctx->message, orig_subject);
-			strbuf_addstr(&ctx->message, "\n");
 		} else {
-			strbuf_addstr(&ctx->message, "Revert \"");
-			strbuf_addstr(&ctx->message, msg.subject);
-			strbuf_addstr(&ctx->message, "\"\n");
+			sequencer_format_revert_header(&ctx->message, msg.subject);
 		}
 		strbuf_addstr(&ctx->message, "\nThis reverts commit ");
 		refer_to_commit(opts, &ctx->message, commit);