1 files changed, 88 insertions, 0 deletions
diff --git a/third_party/git/builtin/merge-recursive.c b/third_party/git/builtin/merge-recursive.c
new file mode 100644
index 000000000000..5b910e351e4d
--- /dev/null
+++ b/third_party/git/builtin/merge-recursive.c
@@ -0,0 +1,88 @@
+#include "builtin.h"
+#include "commit.h"
+#include "tag.h"
+#include "merge-recursive.h"
+#include "xdiff-interface.h"
+
+static const char builtin_merge_recursive_usage[] =
+	"git %s <base>... -- <head> <remote> ...";
+
+static char *better_branch_name(const char *branch)
+{
+	static char githead_env[8 + GIT_MAX_HEXSZ + 1];
+	char *name;
+
+	if (strlen(branch) != the_hash_algo->hexsz)
+		return xstrdup(branch);
+	xsnprintf(githead_env, sizeof(githead_env), "GITHEAD_%s", branch);
+	name = getenv(githead_env);
+	return xstrdup(name ? name : branch);
+}
+
+int cmd_merge_recursive(int argc, const char **argv, const char *prefix)
+{
+	const struct object_id *bases[21];
+	unsigned bases_count = 0;
+	int i, failed;
+	struct object_id h1, h2;
+	struct merge_options o;
+	char *better1, *better2;
+	struct commit *result;
+
+	init_merge_options(&o, the_repository);
+	if (argv[0] && ends_with(argv[0], "-subtree"))
+		o.subtree_shift = "";
+
+	if (argc < 4)
+		usagef(builtin_merge_recursive_usage, argv[0]);
+
+	for (i = 1; i < argc; ++i) {
+		const char *arg = argv[i];
+
+		if (starts_with(arg, "--")) {
+			if (!arg[2])
+				break;
+			if (parse_merge_opt(&o, arg + 2))
+				die(_("unknown option %s"), arg);
+			continue;
+		}
+		if (bases_count < ARRAY_SIZE(bases)-1) {
+			struct object_id *oid = xmalloc(sizeof(struct object_id));
+			if (get_oid(argv[i], oid))
+				die(_("could not parse object '%s'"), argv[i]);
+			bases[bases_count++] = oid;
+		}
+		else
+			warning(Q_("cannot handle more than %d base. "
+				   "Ignoring %s.",
+				   "cannot handle more than %d bases. "
+				   "Ignoring %s.",
+				    (int)ARRAY_SIZE(bases)-1),
+				(int)ARRAY_SIZE(bases)-1, argv[i]);
+	}
+	if (argc - i != 3) /* "--" "<head>" "<remote>" */
+		die(_("not handling anything other than two heads merge."));
+
+	o.branch1 = argv[++i];
+	o.branch2 = argv[++i];
+
+	if (get_oid(o.branch1, &h1))
+		die(_("could not resolve ref '%s'"), o.branch1);
+	if (get_oid(o.branch2, &h2))
+		die(_("could not resolve ref '%s'"), o.branch2);
+
+	o.branch1 = better1 = better_branch_name(o.branch1);
+	o.branch2 = better2 = better_branch_name(o.branch2);
+
+	if (o.verbosity >= 3)
+		printf(_("Merging %s with %s\n"), o.branch1, o.branch2);
+
+	failed = merge_recursive_generic(&o, &h1, &h2, bases_count, bases, &result);
+
+	free(better1);
+	free(better2);
+
+	if (failed < 0)
+		return 128; /* die() error code */
+	return failed;
+}