rebase -r: support merge strategies other than recursive

.gitignore

@@ -122,9 +122,6 @@
 /git-range-diff
 /git-read-tree
 /git-rebase
-/git-rebase--am
-/git-rebase--common
-/git-rebase--interactive
 /git-rebase--preserve-merges
 /git-receive-pack
 /git-reflog

Documentation/git-rebase.txt

@@ -543,8 +543,6 @@ In addition, the following pairs of options are incompatible:
  * --preserve-merges and --interactive
  * --preserve-merges and --signoff
  * --preserve-merges and --rebase-merges
- * --rebase-merges and --strategy
- * --rebase-merges and --strategy-option
 
 BEHAVIORAL DIFFERENCES
 -----------------------

Makefile

@@ -624,8 +624,6 @@ SCRIPT_SH += git-web--browse.sh
 
 SCRIPT_LIB += git-mergetool--lib
 SCRIPT_LIB += git-parse-remote
-SCRIPT_LIB += git-rebase--am
-SCRIPT_LIB += git-rebase--common
 SCRIPT_LIB += git-rebase--preserve-merges
 SCRIPT_LIB += git-sh-setup
 SCRIPT_LIB += git-sh-i18n

builtin/rebase.c

@@ -62,7 +62,7 @@ struct rebase_options {
 	const char *onto_name;
 	const char *revisions;
 	const char *switch_to;
-	int root;
+	int root, root_with_onto;
 	struct object_id *squash_onto;
 	struct commit *restrict_revision;
 	int dont_finish_rebase;
@@ -374,6 +374,7 @@ static int run_rebase_interactive(struct rebase_options *opts,
 	flags |= abbreviate_commands ? TODO_LIST_ABBREVIATE_CMDS : 0;
 	flags |= opts->rebase_merges ? TODO_LIST_REBASE_MERGES : 0;
 	flags |= opts->rebase_cousins > 0 ? TODO_LIST_REBASE_COUSINS : 0;
+	flags |= opts->root_with_onto ? TODO_LIST_ROOT_WITH_ONTO : 0;
 	flags |= command == ACTION_SHORTEN_OIDS ? TODO_LIST_SHORTEN_IDS : 0;
 
 	switch (command) {
@@ -1153,10 +1154,6 @@ static int run_specific_rebase(struct rebase_options *opts, enum action action)
 	}
 
 	switch (opts->type) {
-	case REBASE_AM:
-		backend = "git-rebase--am";
-		backend_func = "git_rebase__am";
-		break;
 	case REBASE_PRESERVE_MERGES:
 		backend = "git-rebase--preserve-merges";
 		backend_func = "git_rebase__preserve_merges";
@@ -1167,8 +1164,7 @@ static int run_specific_rebase(struct rebase_options *opts, enum action action)
 	}
 
 	strbuf_addf(&script_snippet,
-		    ". git-sh-setup && . git-rebase--common &&"
-		    " . %s && %s", backend, backend_func);
+		    ". git-sh-setup && . %s && %s", backend, backend_func);
 	argv[0] = script_snippet.buf;
 
 	status = run_command_v_opt(argv, RUN_USING_SHELL);
@@ -1816,15 +1812,6 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
 			      "'--reschedule-failed-exec'"));
 	}
 
-	if (options.rebase_merges) {
-		if (strategy_options.nr)
-			die(_("cannot combine '--rebase-merges' with "
-			      "'--strategy-option'"));
-		if (options.strategy)
-			die(_("cannot combine '--rebase-merges' with "
-			      "'--strategy'"));
-	}
-
 	if (!options.root) {
 		if (argc < 1) {
 			struct branch *branch;
@@ -1855,7 +1842,9 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
 			options.squash_onto = &squash_onto;
 			options.onto_name = squash_onto_name =
 				xstrdup(oid_to_hex(&squash_onto));
-		}
+		} else
+			options.root_with_onto = 1;
+
 		options.upstream_name = NULL;
 		options.upstream = NULL;
 		if (argc > 1)

git-rebase--preserve-merges.sh

@@ -77,6 +77,61 @@ rewritten_pending="$state_dir"/rewritten-pending
 # and leaves CR at the end instead.
 cr=$(printf "\015")
 
+resolvemsg="
+$(gettext 'Resolve all conflicts manually, mark them as resolved with
+"git add/rm <conflicted_files>", then run "git rebase --continue".
+You can instead skip this commit: run "git rebase --skip".
+To abort and get back to the state before "git rebase", run "git rebase --abort".')
+"
+
+write_basic_state () {
+	echo "$head_name" > "$state_dir"/head-name &&
+	echo "$onto" > "$state_dir"/onto &&
+	echo "$orig_head" > "$state_dir"/orig-head &&
+	test t = "$GIT_QUIET" && : > "$state_dir"/quiet
+	test t = "$verbose" && : > "$state_dir"/verbose
+	test -n "$strategy" && echo "$strategy" > "$state_dir"/strategy
+	test -n "$strategy_opts" && echo "$strategy_opts" > \
+		"$state_dir"/strategy_opts
+	test -n "$allow_rerere_autoupdate" && echo "$allow_rerere_autoupdate" > \
+		"$state_dir"/allow_rerere_autoupdate
+	test -n "$gpg_sign_opt" && echo "$gpg_sign_opt" > "$state_dir"/gpg_sign_opt
+	test -n "$signoff" && echo "$signoff" >"$state_dir"/signoff
+	test -n "$reschedule_failed_exec" && : > "$state_dir"/reschedule-failed-exec
+}
+
+apply_autostash () {
+	if test -f "$state_dir/autostash"
+	then
+		stash_sha1=$(cat "$state_dir/autostash")
+		if git stash apply $stash_sha1 >/dev/null 2>&1
+		then
+			echo "$(gettext 'Applied autostash.')" >&2
+		else
+			git stash store -m "autostash" -q $stash_sha1 ||
+			die "$(eval_gettext "Cannot store \$stash_sha1")"
+			gettext 'Applying autostash resulted in conflicts.
+Your changes are safe in the stash.
+You can run "git stash pop" or "git stash drop" at any time.
+' >&2
+		fi
+	fi
+}
+
+output () {
+	case "$verbose" in
+	'')
+		output=$("$@" 2>&1 )
+		status=$?
+		test $status != 0 && printf "%s\n" "$output"
+		return $status
+		;;
+	*)
+		"$@"
+		;;
+	esac
+}
+
 strategy_args=${strategy:+--strategy=$strategy}
 test -n "$strategy_opts" &&
 eval '

sequencer.c

@@ -767,7 +767,7 @@ static int parse_key_value_squoted(char *buf, struct string_list *list)
  *	GIT_AUTHOR_DATE='$author_date'
  *
  * where $author_name, $author_email and $author_date are quoted. We are strict
- * with our parsing, as the file was meant to be eval'd in the old
+ * with our parsing, as the file was meant to be eval'd in the now-removed
  * git-am.sh/git-rebase--interactive.sh scripts, and thus if the file differs
  * from what this function expects, it is better to bail out than to do
  * something that the user does not expect.
@@ -3256,6 +3256,9 @@ static int do_merge(struct repository *r,
 	struct commit *head_commit, *merge_commit, *i;
 	struct commit_list *bases, *j, *reversed = NULL;
 	struct commit_list *to_merge = NULL, **tail = &to_merge;
+	const char *strategy = !opts->xopts_nr &&
+		(!opts->strategy || !strcmp(opts->strategy, "recursive")) ?
+		NULL : opts->strategy;
 	struct merge_options o;
 	int merge_arg_len, oneline_offset, can_fast_forward, ret, k;
 	static struct lock_file lock;
@@ -3404,7 +3407,7 @@ static int do_merge(struct repository *r,
 		goto leave_merge;
 	}
 
-	if (to_merge->next) {
+	if (strategy || to_merge->next) {
 		/* Octopus merge */
 		struct child_process cmd = CHILD_PROCESS_INIT;
 
@@ -3418,7 +3421,14 @@ static int do_merge(struct repository *r,
 		cmd.git_cmd = 1;
 		argv_array_push(&cmd.args, "merge");
 		argv_array_push(&cmd.args, "-s");
-		argv_array_push(&cmd.args, "octopus");
+		if (!strategy)
+			argv_array_push(&cmd.args, "octopus");
+		else {
+			argv_array_push(&cmd.args, strategy);
+			for (k = 0; k < opts->xopts_nr; k++)
+				argv_array_pushf(&cmd.args,
+						 "-X%s", opts->xopts[k]);
+		}
 		argv_array_push(&cmd.args, "--no-edit");
 		argv_array_push(&cmd.args, "--no-ff");
 		argv_array_push(&cmd.args, "--no-log");
@@ -4430,6 +4440,7 @@ static int make_script_with_merges(struct pretty_print_context *pp,
 {
 	int keep_empty = flags & TODO_LIST_KEEP_EMPTY;
 	int rebase_cousins = flags & TODO_LIST_REBASE_COUSINS;
+	int root_with_onto = flags & TODO_LIST_ROOT_WITH_ONTO;
 	struct strbuf buf = STRBUF_INIT, oneline = STRBUF_INIT;
 	struct strbuf label = STRBUF_INIT;
 	struct commit_list *commits = NULL, **tail = &commits, *iter;
@@ -4596,7 +4607,8 @@ static int make_script_with_merges(struct pretty_print_context *pp,
 
 		if (!commit)
 			strbuf_addf(out, "%s %s\n", cmd_reset,
-				    rebase_cousins ? "onto" : "[new root]");
+				    rebase_cousins || root_with_onto ?
+				    "onto" : "[new root]");
 		else {
 			const char *to = NULL;
 

sequencer.h

@@ -142,6 +142,12 @@ int sequencer_remove_state(struct replay_opts *opts);
  */
 #define TODO_LIST_REBASE_COUSINS (1U << 4)
 #define TODO_LIST_APPEND_TODO_HELP (1U << 5)
+/*
+ * When generating a script that rebases merges with `--root` *and* with
+ * `--onto`, we do not want to re-generate the root commits.
+ */
+#define TODO_LIST_ROOT_WITH_ONTO (1U << 6)
+
 
 int sequencer_make_script(struct repository *r, struct strbuf *out, int argc,
 			  const char **argv, unsigned flags);