1 files changed, 236 insertions, 163 deletions

diff --git a/builtin/revert.c b/builtin/revert.c
index 778a56eb51..57b51e4a0e 100644
--- a/builtin/revert.c
+++ b/builtin/revert.c
@@ -39,29 +39,34 @@ static const char * const cherry_pick_usage[] = {
 static int edit, no_replay, no_commit, mainline, signoff, allow_ff;
 static enum { REVERT, CHERRY_PICK } action;
 static struct commit *commit;
-static const char *commit_name;
+static int commit_argc;
+static const char **commit_argv;
 static int allow_rerere_auto;
 
 static const char *me;
+static const char *strategy;
 
 #define GIT_REFLOG_ACTION "GIT_REFLOG_ACTION"
 
 static char *get_encoding(const char *message);
 
+static const char * const *revert_or_cherry_pick_usage(void)
+{
+	return action == REVERT ? revert_usage : cherry_pick_usage;
+}
+
 static void parse_args(int argc, const char **argv)
 {
-	const char * const * usage_str =
-		action == REVERT ?  revert_usage : cherry_pick_usage;
-	unsigned char sha1[20];
+	const char * const * usage_str = revert_or_cherry_pick_usage();
 	int noop;
 	struct option options[] = {
 		OPT_BOOLEAN('n', "no-commit", &no_commit, "don't automatically commit"),
 		OPT_BOOLEAN('e', "edit", &edit, "edit the commit message"),
-		OPT_BOOLEAN('x', NULL, &no_replay, "append commit name when cherry-picking"),
 		OPT_BOOLEAN('r', NULL, &noop, "no-op (backward compatibility)"),
 		OPT_BOOLEAN('s', "signoff", &signoff, "add Signed-off-by:"),
 		OPT_INTEGER('m', "mainline", &mainline, "parent number"),
 		OPT_RERERE_AUTOUPDATE(&allow_rerere_auto),
+		OPT_STRING(0, "strategy", &strategy, "strategy", "merge strategy"),
 		OPT_END(),
 		OPT_END(),
 		OPT_END(),
@@ -69,6 +74,7 @@ static void parse_args(int argc, const char **argv)
 
 	if (action == CHERRY_PICK) {
 		struct option cp_extra[] = {
+			OPT_BOOLEAN('x', NULL, &no_replay, "append commit name"),
 			OPT_BOOLEAN(0, "ff", &allow_ff, "allow fast-forward"),
 			OPT_END(),
 		};
@@ -76,15 +82,13 @@ static void parse_args(int argc, const char **argv)
 			die("program error");
 	}
 
-	if (parse_options(argc, argv, NULL, options, usage_str, 0) != 1)
+	commit_argc = parse_options(argc, argv, NULL, options, usage_str,
+				    PARSE_OPT_KEEP_ARGV0 |
+				    PARSE_OPT_KEEP_UNKNOWN);
+	if (commit_argc < 2)
 		usage_with_options(usage_str, options);
 
-	commit_name = argv[0];
-	if (get_sha1(commit_name, sha1))
-		die ("Cannot find '%s'", commit_name);
-	commit = lookup_commit_reference(sha1);
-	if (!commit)
-		exit(1);
+	commit_argv = argv;
 }
 
 struct commit_message {
@@ -98,9 +102,9 @@ struct commit_message {
 static int get_message(const char *raw_message, struct commit_message *out)
 {
 	const char *encoding;
-	const char *p, *abbrev, *eol;
+	const char *abbrev, *subject;
+	int abbrev_len, subject_len;
 	char *q;
-	int abbrev_len, oneline_len;
 
 	if (!raw_message)
 		return -1;
@@ -109,34 +113,29 @@ static int get_message(const char *raw_message, struct commit_message *out)
 		encoding = "UTF-8";
 	if (!git_commit_encoding)
 		git_commit_encoding = "UTF-8";
-	if ((out->reencoded_message = reencode_string(raw_message,
-					git_commit_encoding, encoding)))
+
+	out->reencoded_message = NULL;
+	out->message = raw_message;
+	if (strcmp(encoding, git_commit_encoding))
+		out->reencoded_message = reencode_string(raw_message,
+					git_commit_encoding, encoding);
+	if (out->reencoded_message)
 		out->message = out->reencoded_message;
 
 	abbrev = find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV);
 	abbrev_len = strlen(abbrev);
 
-	/* Find beginning and end of commit subject. */
-	p = out->message;
-	while (*p && (*p != '\n' || p[1] != '\n'))
-		p++;
-	if (*p) {
-		p += 2;
-		for (eol = p + 1; *eol && *eol != '\n'; eol++)
-			; /* do nothing */
-	} else
-		eol = p;
-	oneline_len = eol - p;
+	subject_len = find_commit_subject(out->message, &subject);
 
 	out->parent_label = xmalloc(strlen("parent of ") + abbrev_len +
-			      strlen("... ") + oneline_len + 1);
+			      strlen("... ") + subject_len + 1);
 	q = out->parent_label;
 	q = mempcpy(q, "parent of ", strlen("parent of "));
 	out->label = q;
 	q = mempcpy(q, abbrev, abbrev_len);
 	q = mempcpy(q, "... ", strlen("... "));
 	out->subject = q;
-	q = mempcpy(q, p, oneline_len);
+	q = mempcpy(q, subject, subject_len);
 	*q = '\0';
 	return 0;
 }
@@ -169,28 +168,17 @@ static char *get_encoding(const char *message)
 	return NULL;
 }
 
-static struct lock_file msg_file;
-static int msg_fd;
-
-static void add_to_msg(const char *string)
-{
-	int len = strlen(string);
-	if (write_in_full(msg_fd, string, len) < 0)
-		die_errno ("Could not write to MERGE_MSG");
-}
-
-static void add_message_to_msg(const char *message)
+static void add_message_to_msg(struct strbuf *msgbuf, const char *message)
 {
 	const char *p = message;
 	while (*p && (*p != '\n' || p[1] != '\n'))
 		p++;
 
 	if (!*p)
-		add_to_msg(sha1_to_hex(commit->object.sha1));
+		strbuf_addstr(msgbuf, sha1_to_hex(commit->object.sha1));
 
 	p += 2;
-	add_to_msg(p);
-	return;
+	strbuf_addstr(msgbuf, p);
 }
 
 static void set_author_ident_env(const char *message)
@@ -243,27 +231,43 @@ static void set_author_ident_env(const char *message)
 			sha1_to_hex(commit->object.sha1));
 }
 
-static char *help_msg(const char *name)
+static void advise(const char *advice, ...)
 {
-	struct strbuf helpbuf = STRBUF_INIT;
-	char *msg = getenv("GIT_CHERRY_PICK_HELP");
+	va_list params;
 
-	if (msg)
-		return msg;
+	va_start(params, advice);
+	vreportf("hint: ", advice, params);
+	va_end(params);
+}
 
-	strbuf_addstr(&helpbuf, "  After resolving the conflicts,\n"
-		"mark the corrected paths with 'git add <paths>' or 'git rm <paths>'\n"
-		"and commit the result");
+static void print_advice(void)
+{
+	char *msg = getenv("GIT_CHERRY_PICK_HELP");
 
-	if (action == CHERRY_PICK) {
-		strbuf_addf(&helpbuf, " with: \n"
-			"\n"
-			"        git commit -c %s\n",
-			name);
+	if (msg) {
+		fprintf(stderr, "%s\n", msg);
+		return;
 	}
-	else
-		strbuf_addch(&helpbuf, '.');
-	return strbuf_detach(&helpbuf, NULL);
+
+	advise("after resolving the conflicts, mark the corrected paths");
+	advise("with 'git add <paths>' or 'git rm <paths>'");
+
+	if (action == CHERRY_PICK)
+		advise("and commit the result with 'git commit -c %s'",
+		       find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV));
+}
+
+static void write_message(struct strbuf *msgbuf, const char *filename)
+{
+	static struct lock_file msg_file;
+
+	int msg_fd = hold_lock_file_for_update(&msg_file, filename,
+					       LOCK_DIE_ON_ERROR);
+	if (write_in_full(msg_fd, msgbuf->buf, msgbuf->len) < 0)
+		die_errno("Could not write to %s.", filename);
+	strbuf_release(msgbuf);
+	if (commit_lock_file(&msg_file) < 0)
+		die("Error wrapping up %s", filename);
 }
 
 static struct tree *empty_tree(void)
@@ -300,40 +304,99 @@ static int fast_forward_to(const unsigned char *to, const unsigned char *from)
 	return write_ref_sha1(ref_lock, to, "cherry-pick");
 }
 
-static int revert_or_cherry_pick(int argc, const char **argv)
+static int do_recursive_merge(struct commit *base, struct commit *next,
+			      const char *base_label, const char *next_label,
+			      unsigned char *head, struct strbuf *msgbuf)
 {
-	unsigned char head[20];
-	struct commit *base, *next, *parent;
-	const char *base_label, *next_label;
-	int i, index_fd, clean;
-	struct commit_message msg = { NULL, NULL, NULL, NULL, NULL };
-	char *defmsg = NULL;
 	struct merge_options o;
 	struct tree *result, *next_tree, *base_tree, *head_tree;
+	int clean, index_fd;
 	static struct lock_file index_lock;
 
-	git_config(git_default_config, NULL);
-	me = action == REVERT ? "revert" : "cherry-pick";
-	setenv(GIT_REFLOG_ACTION, me, 0);
-	parse_args(argc, argv);
+	index_fd = hold_locked_index(&index_lock, 1);
 
-	/* this is copied from the shell script, but it's never triggered... */
-	if (action == REVERT && !no_replay)
-		die("revert is incompatible with replay");
+	read_cache();
 
-	if (allow_ff) {
-		if (signoff)
-			die("cherry-pick --ff cannot be used with --signoff");
-		if (no_commit)
-			die("cherry-pick --ff cannot be used with --no-commit");
-		if (no_replay)
-			die("cherry-pick --ff cannot be used with -x");
-		if (edit)
-			die("cherry-pick --ff cannot be used with --edit");
+	/*
+	 * NEEDSWORK: cherry-picking between branches with
+	 * different end-of-line normalization is a pain;
+	 * plumb in an option to set o.renormalize?
+	 * (or better: arbitrary -X options)
+	 */
+	init_merge_options(&o);
+	o.ancestor = base ? base_label : "(empty tree)";
+	o.branch1 = "HEAD";
+	o.branch2 = next ? next_label : "(empty tree)";
+
+	head_tree = parse_tree_indirect(head);
+	next_tree = next ? next->tree : empty_tree();
+	base_tree = base ? base->tree : empty_tree();
+
+	clean = merge_trees(&o,
+			    head_tree,
+			    next_tree, base_tree, &result);
+
+	if (active_cache_changed &&
+	    (write_cache(index_fd, active_cache, active_nr) ||
+	     commit_locked_index(&index_lock)))
+		die("%s: Unable to write new index file", me);
+	rollback_lock_file(&index_lock);
+
+	if (!clean) {
+		int i;
+		strbuf_addstr(msgbuf, "\nConflicts:\n\n");
+		for (i = 0; i < active_nr;) {
+			struct cache_entry *ce = active_cache[i++];
+			if (ce_stage(ce)) {
+				strbuf_addch(msgbuf, '\t');
+				strbuf_addstr(msgbuf, ce->name);
+				strbuf_addch(msgbuf, '\n');
+				while (i < active_nr && !strcmp(ce->name,
+						active_cache[i]->name))
+					i++;
+			}
+		}
 	}
 
-	if (read_cache() < 0)
-		die("git %s: failed to read the index", me);
+	return !clean;
+}
+
+/*
+ * If we are cherry-pick, and if the merge did not result in
+ * hand-editing, we will hit this commit and inherit the original
+ * author date and name.
+ * If we are revert, or if our cherry-pick results in a hand merge,
+ * we had better say that the current user is responsible for that.
+ */
+static int run_git_commit(const char *defmsg)
+{
+	/* 6 is max possible length of our args array including NULL */
+	const char *args[6];
+	int i = 0;
+
+	args[i++] = "commit";
+	args[i++] = "-n";
+	if (signoff)
+		args[i++] = "-s";
+	if (!edit) {
+		args[i++] = "-F";
+		args[i++] = defmsg;
+	}
+	args[i] = NULL;
+
+	return run_command_v_opt(args, RUN_GIT_CMD);
+}
+
+static int do_pick_commit(void)
+{
+	unsigned char head[20];
+	struct commit *base, *next, *parent;
+	const char *base_label, *next_label;
+	struct commit_message msg = { NULL, NULL, NULL, NULL, NULL };
+	char *defmsg = NULL;
+	struct strbuf msgbuf = STRBUF_INIT;
+	int res;
+
 	if (no_commit) {
 		/*
 		 * We do not intend to commit immediately.  We just want to
@@ -379,7 +442,7 @@ static int revert_or_cherry_pick(int argc, const char **argv)
 	else
 		parent = commit->parents->item;
 
-	if (allow_ff && !hashcmp(parent->object.sha1, head))
+	if (allow_ff && parent && !hashcmp(parent->object.sha1, head))
 		return fast_forward_to(commit->object.sha1, head);
 
 	if (parent && parse_commit(parent) < 0)
@@ -398,110 +461,122 @@ static int revert_or_cherry_pick(int argc, const char **argv)
 	 */
 
 	defmsg = git_pathdup("MERGE_MSG");
-	msg_fd = hold_lock_file_for_update(&msg_file, defmsg,
-					   LOCK_DIE_ON_ERROR);
-
-	index_fd = hold_locked_index(&index_lock, 1);
 
 	if (action == REVERT) {
 		base = commit;
 		base_label = msg.label;
 		next = parent;
 		next_label = msg.parent_label;
-		add_to_msg("Revert \"");
-		add_to_msg(msg.subject);
-		add_to_msg("\"\n\nThis reverts commit ");
-		add_to_msg(sha1_to_hex(commit->object.sha1));
+		strbuf_addstr(&msgbuf, "Revert \"");
+		strbuf_addstr(&msgbuf, msg.subject);
+		strbuf_addstr(&msgbuf, "\"\n\nThis reverts commit ");
+		strbuf_addstr(&msgbuf, sha1_to_hex(commit->object.sha1));
 
 		if (commit->parents->next) {
-			add_to_msg(", reversing\nchanges made to ");
-			add_to_msg(sha1_to_hex(parent->object.sha1));
+			strbuf_addstr(&msgbuf, ", reversing\nchanges made to ");
+			strbuf_addstr(&msgbuf, sha1_to_hex(parent->object.sha1));
 		}
-		add_to_msg(".\n");
+		strbuf_addstr(&msgbuf, ".\n");
 	} else {
 		base = parent;
 		base_label = msg.parent_label;
 		next = commit;
 		next_label = msg.label;
 		set_author_ident_env(msg.message);
-		add_message_to_msg(msg.message);
+		add_message_to_msg(&msgbuf, msg.message);
 		if (no_replay) {
-			add_to_msg("(cherry picked from commit ");
-			add_to_msg(sha1_to_hex(commit->object.sha1));
-			add_to_msg(")\n");
+			strbuf_addstr(&msgbuf, "(cherry picked from commit ");
+			strbuf_addstr(&msgbuf, sha1_to_hex(commit->object.sha1));
+			strbuf_addstr(&msgbuf, ")\n");
 		}
 	}
 
-	read_cache();
-	init_merge_options(&o);
-	o.ancestor = base ? base_label : "(empty tree)";
-	o.branch1 = "HEAD";
-	o.branch2 = next ? next_label : "(empty tree)";
-
-	head_tree = parse_tree_indirect(head);
-	next_tree = next ? next->tree : empty_tree();
-	base_tree = base ? base->tree : empty_tree();
+	if (!strategy || !strcmp(strategy, "recursive") || action == REVERT) {
+		res = do_recursive_merge(base, next, base_label, next_label,
+					 head, &msgbuf);
+		write_message(&msgbuf, defmsg);
+	} else {
+		struct commit_list *common = NULL;
+		struct commit_list *remotes = NULL;
 
-	clean = merge_trees(&o,
-			    head_tree,
-			    next_tree, base_tree, &result);
+		write_message(&msgbuf, defmsg);
 
-	if (active_cache_changed &&
-	    (write_cache(index_fd, active_cache, active_nr) ||
-	     commit_locked_index(&index_lock)))
-		die("%s: Unable to write new index file", me);
-	rollback_lock_file(&index_lock);
+		commit_list_insert(base, &common);
+		commit_list_insert(next, &remotes);
+		res = try_merge_command(strategy, common,
+					sha1_to_hex(head), remotes);
+		free_commit_list(common);
+		free_commit_list(remotes);
+	}
 
-	if (!clean) {
-		add_to_msg("\nConflicts:\n\n");
-		for (i = 0; i < active_nr;) {
-			struct cache_entry *ce = active_cache[i++];
-			if (ce_stage(ce)) {
-				add_to_msg("\t");
-				add_to_msg(ce->name);
-				add_to_msg("\n");
-				while (i < active_nr && !strcmp(ce->name,
-						active_cache[i]->name))
-					i++;
-			}
-		}
-		if (commit_lock_file(&msg_file) < 0)
-			die ("Error wrapping up %s", defmsg);
-		fprintf(stderr, "Automatic %s failed.%s\n",
-			me, help_msg(commit_name));
+	if (res) {
+		error("could not %s %s... %s",
+		      action == REVERT ? "revert" : "apply",
+		      find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV),
+		      msg.subject);
+		print_advice();
 		rerere(allow_rerere_auto);
-		exit(1);
+	} else {
+		if (!no_commit)
+			res = run_git_commit(defmsg);
 	}
-	if (commit_lock_file(&msg_file) < 0)
-		die ("Error wrapping up %s", defmsg);
-	fprintf(stderr, "Finished one %s.\n", me);
 
-	/*
-	 *
-	 * If we are cherry-pick, and if the merge did not result in
-	 * hand-editing, we will hit this commit and inherit the original
-	 * author date and name.
-	 * If we are revert, or if our cherry-pick results in a hand merge,
-	 * we had better say that the current user is responsible for that.
-	 */
+	free_message(&msg);
+	free(defmsg);
+
+	return res;
+}
+
+static void prepare_revs(struct rev_info *revs)
+{
+	int argc;
 
-	if (!no_commit) {
-		/* 6 is max possible length of our args array including NULL */
-		const char *args[6];
-		int i = 0;
-		args[i++] = "commit";
-		args[i++] = "-n";
+	init_revisions(revs, NULL);
+	revs->no_walk = 1;
+	if (action != REVERT)
+		revs->reverse = 1;
+
+	argc = setup_revisions(commit_argc, commit_argv, revs, NULL);
+	if (argc > 1)
+		usage(*revert_or_cherry_pick_usage());
+
+	if (prepare_revision_walk(revs))
+		die("revision walk setup failed");
+
+	if (!revs->commits)
+		die("empty commit set passed");
+}
+
+static int revert_or_cherry_pick(int argc, const char **argv)
+{
+	struct rev_info revs;
+
+	git_config(git_default_config, NULL);
+	me = action == REVERT ? "revert" : "cherry-pick";
+	setenv(GIT_REFLOG_ACTION, me, 0);
+	parse_args(argc, argv);
+
+	if (allow_ff) {
 		if (signoff)
-			args[i++] = "-s";
-		if (!edit) {
-			args[i++] = "-F";
-			args[i++] = defmsg;
-		}
-		args[i] = NULL;
-		return execv_git_cmd(args);
+			die("cherry-pick --ff cannot be used with --signoff");
+		if (no_commit)
+			die("cherry-pick --ff cannot be used with --no-commit");
+		if (no_replay)
+			die("cherry-pick --ff cannot be used with -x");
+		if (edit)
+			die("cherry-pick --ff cannot be used with --edit");
+	}
+
+	if (read_cache() < 0)
+		die("git %s: failed to read the index", me);
+
+	prepare_revs(&revs);
+
+	while ((commit = get_revision(&revs))) {
+		int res = do_pick_commit();
+		if (res)
+			return res;
 	}
-	free_message(&msg);
-	free(defmsg);
 
 	return 0;
 }
@@ -510,14 +585,12 @@ int cmd_revert(int argc, const char **argv, const char *prefix)
 {
 	if (isatty(0))
 		edit = 1;
-	no_replay = 1;
 	action = REVERT;
 	return revert_or_cherry_pick(argc, argv);
 }
 
 int cmd_cherry_pick(int argc, const char **argv, const char *prefix)
 {
-	no_replay = 0;
 	action = CHERRY_PICK;
 	return revert_or_cherry_pick(argc, argv);
 }