Merge branch 'js/rebase-recreate-merge'

"git rebase" learned "--rebase-merges" to transplant the whole
topology of commit graph elsewhere.

* js/rebase-recreate-merge:
  rebase -i --rebase-merges: add a section to the man page
  rebase -i: introduce --rebase-merges=[no-]rebase-cousins
  pull: accept --rebase=merges to recreate the branch topology
  rebase --rebase-merges: avoid "empty merges"
  sequencer: handle post-rewrite for merge commands
  sequencer: make refs generated by the `label` command worktree-local
  rebase --rebase-merges: add test for --keep-empty
  rebase: introduce the --rebase-merges option
  rebase-helper --make-script: introduce a flag to rebase merges
  sequencer: fast-forward `merge` commands, if possible
  sequencer: introduce the `merge` command
  sequencer: introduce new commands to reset the revision
  git-rebase--interactive: clarify arguments
  sequencer: offer helpful advice when a command was rescheduled
  sequencer: refactor how original todo list lines are accessed
  sequencer: make rearrange_squash() a bit more obvious
  sequencer: avoid using errno clobbered by rollback_lock_file()

3 files changed, 35 insertions, 10 deletions

diff --git a/builtin/pull.c b/builtin/pull.c
index 71aac5005e..c719a4f9d7 100644
--- a/builtin/pull.c
+++ b/builtin/pull.c
@@ -27,14 +27,16 @@ enum rebase_type {
 	REBASE_FALSE = 0,
 	REBASE_TRUE,
 	REBASE_PRESERVE,
+	REBASE_MERGES,
 	REBASE_INTERACTIVE
 };
 
 /**
  * Parses the value of --rebase. If value is a false value, returns
  * REBASE_FALSE. If value is a true value, returns REBASE_TRUE. If value is
- * "preserve", returns REBASE_PRESERVE. If value is a invalid value, dies with
- * a fatal error if fatal is true, otherwise returns REBASE_INVALID.
+ * "merges", returns REBASE_MERGES. If value is "preserve", returns
+ * REBASE_PRESERVE. If value is a invalid value, dies with a fatal error if
+ * fatal is true, otherwise returns REBASE_INVALID.
  */
 static enum rebase_type parse_config_rebase(const char *key, const char *value,
 		int fatal)
@@ -47,6 +49,8 @@ static enum rebase_type parse_config_rebase(const char *key, const char *value,
 		return REBASE_TRUE;
 	else if (!strcmp(value, "preserve"))
 		return REBASE_PRESERVE;
+	else if (!strcmp(value, "merges"))
+		return REBASE_MERGES;
 	else if (!strcmp(value, "interactive"))
 		return REBASE_INTERACTIVE;
 
@@ -130,7 +134,7 @@ static struct option pull_options[] = {
 	/* Options passed to git-merge or git-rebase */
 	OPT_GROUP(N_("Options related to merging")),
 	{ OPTION_CALLBACK, 'r', "rebase", &opt_rebase,
-	  "false|true|preserve|interactive",
+	  "false|true|merges|preserve|interactive",
 	  N_("incorporate changes by rebasing rather than merging"),
 	  PARSE_OPT_OPTARG, parse_opt_rebase },
 	OPT_PASSTHRU('n', NULL, &opt_diffstat, NULL,
@@ -800,7 +804,9 @@ static int run_rebase(const struct object_id *curr_head,
 	argv_push_verbosity(&args);
 
 	/* Options passed to git-rebase */
-	if (opt_rebase == REBASE_PRESERVE)
+	if (opt_rebase == REBASE_MERGES)
+		argv_array_push(&args, "--rebase-merges");
+	else if (opt_rebase == REBASE_PRESERVE)
 		argv_array_push(&args, "--preserve-merges");
 	else if (opt_rebase == REBASE_INTERACTIVE)
 		argv_array_push(&args, "--interactive");
diff --git a/builtin/rebase--helper.c b/builtin/rebase--helper.c
index ad074705bb..f7c2a5fdc8 100644
--- a/builtin/rebase--helper.c
+++ b/builtin/rebase--helper.c
@@ -12,8 +12,8 @@ static const char * const builtin_rebase_helper_usage[] = {
 int cmd_rebase__helper(int argc, const char **argv, const char *prefix)
 {
 	struct replay_opts opts = REPLAY_OPTS_INIT;
-	unsigned flags = 0, keep_empty = 0;
-	int abbreviate_commands = 0;
+	unsigned flags = 0, keep_empty = 0, rebase_merges = 0;
+	int abbreviate_commands = 0, rebase_cousins = -1;
 	enum {
 		CONTINUE = 1, ABORT, MAKE_SCRIPT, SHORTEN_OIDS, EXPAND_OIDS,
 		CHECK_TODO_LIST, SKIP_UNNECESSARY_PICKS, REARRANGE_SQUASH,
@@ -24,6 +24,9 @@ int cmd_rebase__helper(int argc, const char **argv, const char *prefix)
 		OPT_BOOL(0, "keep-empty", &keep_empty, N_("keep empty commits")),
 		OPT_BOOL(0, "allow-empty-message", &opts.allow_empty_message,
 			N_("allow commits with empty messages")),
+		OPT_BOOL(0, "rebase-merges", &rebase_merges, N_("rebase merge commits")),
+		OPT_BOOL(0, "rebase-cousins", &rebase_cousins,
+			 N_("keep original branch points of cousins")),
 		OPT_CMDMODE(0, "continue", &command, N_("continue rebase"),
 				CONTINUE),
 		OPT_CMDMODE(0, "abort", &command, N_("abort rebase"),
@@ -57,8 +60,14 @@ int cmd_rebase__helper(int argc, const char **argv, const char *prefix)
 
 	flags |= keep_empty ? TODO_LIST_KEEP_EMPTY : 0;
 	flags |= abbreviate_commands ? TODO_LIST_ABBREVIATE_CMDS : 0;
+	flags |= rebase_merges ? TODO_LIST_REBASE_MERGES : 0;
+	flags |= rebase_cousins > 0 ? TODO_LIST_REBASE_COUSINS : 0;
 	flags |= command == SHORTEN_OIDS ? TODO_LIST_SHORTEN_IDS : 0;
 
+	if (rebase_cousins >= 0 && !rebase_merges)
+		warning(_("--[no-]rebase-cousins has no effect without "
+			  "--rebase-merges"));
+
 	if (command == CONTINUE && argc == 1)
 		return !!sequencer_continue(&opts);
 	if (command == ABORT && argc == 1)
diff --git a/builtin/remote.c b/builtin/remote.c
index 8708e584e9..0bbf9f4c9e 100644
--- a/builtin/remote.c
+++ b/builtin/remote.c
@@ -245,7 +245,9 @@ static int add(int argc, const char **argv)
 struct branch_info {
 	char *remote_name;
 	struct string_list merge;
-	enum { NO_REBASE, NORMAL_REBASE, INTERACTIVE_REBASE } rebase;
+	enum {
+		NO_REBASE, NORMAL_REBASE, INTERACTIVE_REBASE, REBASE_MERGES
+	} rebase;
 };
 
 static struct string_list branch_list = STRING_LIST_INIT_NODUP;
@@ -306,6 +308,8 @@ static int config_read_branches(const char *key, const char *value, void *cb)
 				info->rebase = v;
 			else if (!strcmp(value, "preserve"))
 				info->rebase = NORMAL_REBASE;
+			else if (!strcmp(value, "merges"))
+				info->rebase = REBASE_MERGES;
 			else if (!strcmp(value, "interactive"))
 				info->rebase = INTERACTIVE_REBASE;
 		}
@@ -963,9 +967,15 @@ static int show_local_info_item(struct string_list_item *item, void *cb_data)
 
 	printf("    %-*s ", show_info->width, item->string);
 	if (branch_info->rebase) {
-		printf_ln(branch_info->rebase == INTERACTIVE_REBASE
-			  ? _("rebases interactively onto remote %s")
-			  : _("rebases onto remote %s"), merge->items[0].string);
+		const char *msg;
+		if (branch_info->rebase == INTERACTIVE_REBASE)
+			msg = _("rebases interactively onto remote %s");
+		else if (branch_info->rebase == REBASE_MERGES)
+			msg = _("rebases interactively (with merges) onto "
+				"remote %s");
+		else
+			msg = _("rebases onto remote %s");
+		printf_ln(msg, merge->items[0].string);
 		return 0;
 	} else if (show_info->any_rebase) {
 		printf_ln(_(" merges with remote %s"), merge->items[0].string);