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[PATCH/RFC] Support --append-trailer in cherry-pick and revert

From
Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Date
Nov 6, 2018, 17:16 UTC
Message-ID
<20181106171637.15562-1-pclouds@gmail.com>
In-Reply-To
<20181104181026.8451-1-pclouds@gmail.com>

OK here is a less constroversal attempt to add new trailers. Instead of changing the default behavior (which could be done incrementally later), this patch simply adds a new option --append-trailer to revert and cherry-pick.

Both will show either
    Reverts: <commit>[~<num>]
or
    Cherry-picked-from: <commit>[~<num>]

--append-trailer could be added to more commands (e.g. merge) that generate commit messages if they have something for machine consumption.

After this, perhaps we could have a config key to turn this on by default (for revert; for cherry-pick it will turn off "-x" too). Then after a couple releases, the we got good reception, we'll make it default?

No tests, no proper commit message since I think we're still going to discuss a bit more before settling down.

PS. maybe --append-trailer is too generic? We have --signoff which is also a trailer. But that one carries more weights than just "machine generated tags".

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
---
 Documentation/git-cherry-pick.txt |  6 +++++
 Documentation/git-revert.txt      |  6 +++++
 builtin/revert.c                  |  7 ++++++
 sequencer.c                       | 39 +++++++++++++++++++++++++++----
 sequencer.h                       |  1 +
 5 files changed, 55 insertions(+), 4 deletions(-)
diff --git a/Documentation/git-cherry-pick.txt b/Documentation/git-cherry-pick.txt
index d35d771fc8..b5dff29ead 100644
--- a/Documentation/git-cherry-pick.txt
+++ b/Documentation/git-cherry-pick.txt
@@ -102,6 +102,12 @@ effect to your index in a row.
 	Add Signed-off-by line at the end of the commit message.
 	See the signoff option in linkgit:git-commit[1] for more information.
 
+--append-trailer::
+	When recording a commit, append a "Cherry-picked-from:" line
+	with object name of the cherry-picked commit. If a merge is
+	cherry-picked with `-m`, the extended SHA-1 syntax is used
+	to indicate the side of the merge to be cherry-picked.
+
 -S[<keyid>]::
 --gpg-sign[=<keyid>]::
 	GPG-sign commits. The `keyid` argument is optional and
diff --git a/Documentation/git-revert.txt b/Documentation/git-revert.txt
index 837707a8fd..e08010b200 100644
--- a/Documentation/git-revert.txt
+++ b/Documentation/git-revert.txt
@@ -91,6 +91,12 @@ effect to your index in a row.
 	Add Signed-off-by line at the end of the commit message.
 	See the signoff option in linkgit:git-commit[1] for more information.
 
+--append-trailer::
+	When recording a commit, append a "Cherry-picked-from:" line
+	with object name of the cherry-picked commit. If a merge is
+	cherry-picked with `-m`, the extended SHA-1 syntax is used
+	to indicate the side of the merge to be cherry-picked.
+
 --strategy=<strategy>::
 	Use the given merge strategy.  Should only be used once.
 	See the MERGE STRATEGIES section in linkgit:git-merge[1]
diff --git a/builtin/revert.c b/builtin/revert.c
index c93393c89b..3bd8f57b90 100644
--- a/builtin/revert.c
+++ b/builtin/revert.c
@@ -119,6 +119,7 @@ static int run_sequencer(int argc, const char **argv, struct replay_opts *opts)
 	if (opts->action == REPLAY_PICK) {
 		struct option cp_extra[] = {
 			OPT_BOOL('x', NULL, &opts->record_origin, N_("append commit name")),
+			OPT_BOOL(0, "append-trailer", &opts->append_trailer, N_("record cherry picked commit as trailer")),
 			OPT_BOOL(0, "ff", &opts->allow_ff, N_("allow fast-forward")),
 			OPT_BOOL(0, "allow-empty", &opts->allow_empty, N_("preserve initially empty commits")),
 			OPT_BOOL(0, "allow-empty-message", &opts->allow_empty_message, N_("allow commits with empty messages")),
@@ -126,6 +127,12 @@ static int run_sequencer(int argc, const char **argv, struct replay_opts *opts)
 			OPT_END(),
 		};
 		options = parse_options_concat(options, cp_extra);
+	} else if (opts->action == REPLAY_REVERT) {
+		struct option cp_extra[] = {
+			OPT_BOOL(0, "append-trailer", &opts->append_trailer, N_("record reverted commit as trailer")),
+			OPT_END(),
+		};
+		options = parse_options_concat(options, cp_extra);
 	}
 
 	argc = parse_options(argc, argv, NULL, options, usage_str,
diff --git a/sequencer.c b/sequencer.c
index 9e1ab3a2a7..e8fa307109 100644
--- a/sequencer.c
+++ b/sequencer.c
@@ -911,7 +911,7 @@ static int run_git_commit(const char *defmsg, struct replay_opts *opts,
 	if ((flags & EDIT_MSG))
 		argv_array_push(&cmd.args, "-e");
 	else if (!(flags & CLEANUP_MSG) &&
-		 !opts->signoff && !opts->record_origin &&
+		 !opts->signoff && !opts->record_origin && !opts->append_trailer &&
 		 git_config_get_value("commit.cleanup", &value))
 		argv_array_push(&cmd.args, "--cleanup=verbatim");
 
@@ -1669,7 +1669,7 @@ static int do_pick_commit(enum todo_command command, struct commit *commit,
 	char *author = NULL;
 	struct commit_message msg = { NULL, NULL, NULL, NULL };
 	struct strbuf msgbuf = STRBUF_INIT;
-	int res, unborn = 0, allow;
+	int res, unborn = 0, allow, parent_id = -1;
 
 	if (opts->no_commit) {
 		/*
@@ -1716,6 +1716,7 @@ static int do_pick_commit(enum todo_command command, struct commit *commit,
 			return error(_("commit %s does not have parent %d"),
 				oid_to_hex(&commit->object.oid), opts->mainline);
 		parent = p->item;
+		parent_id = cnt;
 	} else if (0 < opts->mainline)
 		return error(_("mainline was specified but commit %s is not a merge."),
 			oid_to_hex(&commit->object.oid));
@@ -1768,6 +1769,17 @@ static int do_pick_commit(enum todo_command command, struct commit *commit,
 			strbuf_addstr(&msgbuf, oid_to_hex(&parent->object.oid));
 		}
 		strbuf_addstr(&msgbuf, ".\n");
+
+		if (opts->append_trailer) {
+			strbuf_addstr(&msgbuf, "\n");
+			if (parent_id != -1)
+				strbuf_addf(&msgbuf, "Reverts: %s~%d\n",
+					    oid_to_hex(&commit->object.oid),
+					    parent_id);
+			else
+				strbuf_addf(&msgbuf, "Reverts: %s\n",
+					    oid_to_hex(&commit->object.oid));
+		}
 	} else {
 		const char *p;
 
@@ -1780,14 +1792,28 @@ static int do_pick_commit(enum todo_command command, struct commit *commit,
 		if (find_commit_subject(msg.message, &p))
 			strbuf_addstr(&msgbuf, p);
 
-		if (opts->record_origin) {
+		if (opts->record_origin || opts->append_trailer) {
 			strbuf_complete_line(&msgbuf);
 			if (!has_conforming_footer(&msgbuf, NULL, 0))
 				strbuf_addch(&msgbuf, '\n');
+		}
+
+		if (opts->record_origin) {
 			strbuf_addstr(&msgbuf, cherry_picked_prefix);
 			strbuf_addstr(&msgbuf, oid_to_hex(&commit->object.oid));
 			strbuf_addstr(&msgbuf, ")\n");
 		}
+		if (opts->append_trailer) {
+			if (opts->record_origin)
+				strbuf_addstr(&msgbuf, "\n");
+			if (parent_id != -1)
+				strbuf_addf(&msgbuf, "Cherry-picked-from: %s~%d\n",
+					    oid_to_hex(&commit->object.oid),
+					    parent_id);
+			else
+				strbuf_addf(&msgbuf, "Cherry-picked-from: %s\n",
+					    oid_to_hex(&commit->object.oid));
+		}
 		if (!is_fixup(command))
 			author = get_author(msg.message);
 	}
@@ -2227,6 +2253,8 @@ static int populate_opts_cb(const char *key, const char *value, void *data)
 		opts->signoff = git_config_bool_or_int(key, value, &error_flag);
 	else if (!strcmp(key, "options.record-origin"))
 		opts->record_origin = git_config_bool_or_int(key, value, &error_flag);
+	else if (!strcmp(key, "options.append-trailer"))
+		opts->append_trailer = git_config_bool_or_int(key, value, &error_flag);
 	else if (!strcmp(key, "options.allow-ff"))
 		opts->allow_ff = git_config_bool_or_int(key, value, &error_flag);
 	else if (!strcmp(key, "options.mainline"))
@@ -2618,6 +2646,8 @@ static int save_opts(struct replay_opts *opts)
 		res |= git_config_set_in_file_gently(opts_file, "options.signoff", "true");
 	if (opts->record_origin)
 		res |= git_config_set_in_file_gently(opts_file, "options.record-origin", "true");
+	if (opts->append_trailer)
+		res |= git_config_set_in_file_gently(opts_file, "options.append-trailer", "true");
 	if (opts->allow_ff)
 		res |= git_config_set_in_file_gently(opts_file, "options.allow-ff", "true");
 	if (opts->mainline) {
@@ -3432,7 +3462,8 @@ static int pick_commits(struct todo_list *todo_list, struct replay_opts *opts)
 	setenv(GIT_REFLOG_ACTION, action_name(opts), 0);
 	if (opts->allow_ff)
 		assert(!(opts->signoff || opts->no_commit ||
-				opts->record_origin || opts->edit));
+			 opts->record_origin || opts->append_trailer ||
+			 opts->edit));
 	if (read_and_refresh_cache(opts))
 		return -1;
 
diff --git a/sequencer.h b/sequencer.h
index 660cff5050..7d7c1fe6b4 100644
--- a/sequencer.h
+++ b/sequencer.h
@@ -31,6 +31,7 @@ struct replay_opts {
 	/* Boolean options */
 	int edit;
 	int record_origin;
+	int append_trailer;
 	int no_commit;
 	int signoff;
 	int allow_ff;

-- 
2.19.1.1005.gac84295441
Previous: Duy NguyenNext: Ævar Arnfjörð Bjarmason
Message 9 of 25 in “sequencer.c: record revert/cherry-pick commit with trailer lines”
  1. sequencer.c: record revert/cherry-pick commit with trailer linesNguyễn Thái Ngọc Duy, Nov 4, 2018
  2. Phillip WoodNov 4, 2018
  3. Duy NguyenNov 4, 2018
  4. Phillip WoodNov 4, 2018
  5. Johannes SchindelinNov 5, 2018
  6. sequencer.c: record revert/cherry-pick commit with trailer linesNguyễn Thái Ngọc Duy, Nov 4, 2018
  7. brian m. carlsonNov 4, 2018
  8. Duy NguyenNov 5, 2018
  9. Support --append-trailer in cherry-pick and revertNguyễn Thái Ngọc Duy, Nov 6, 2018
  10. Ævar Arnfjörð BjarmasonNov 6, 2018
  11. Jeff KingNov 6, 2018
  12. Jeff KingNov 6, 2018
  13. Junio C HamanoNov 7, 2018
  14. Duy NguyenNov 7, 2018
  15. Jeff KingNov 7, 2018
  16. Junio C HamanoNov 8, 2018
  17. Jeff KingNov 8, 2018
  18. Junio C HamanoNov 8, 2018
  19. Junio C HamanoNov 7, 2018
  20. Junio C HamanoNov 5, 2018
  21. Duy NguyenNov 5, 2018
  22. Junio C HamanoNov 6, 2018
  23. Ævar Arnfjörð BjarmasonNov 6, 2018
  24. Duy NguyenNov 6, 2018
  25. Ævar Arnfjörð BjarmasonNov 6, 2018

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