1 files changed, 38 insertions, 8 deletions

diff --git a/builtin/read-tree.c b/builtin/read-tree.c
index 8ba64bc785..78d3193659 100644
--- a/builtin/read-tree.c
+++ b/builtin/read-tree.c
@@ -15,18 +15,21 @@
 #include "builtin.h"
 #include "parse-options.h"
 #include "resolve-undo.h"
+#include "submodule.h"
+#include "submodule-config.h"
 
 static int nr_trees;
 static int read_empty;
 static struct tree *trees[MAX_UNPACK_TREES];
+static int recurse_submodules = RECURSE_SUBMODULES_DEFAULT;
 
-static int list_tree(unsigned char *sha1)
+static int list_tree(struct object_id *oid)
 {
 	struct tree *tree;
 
 	if (nr_trees >= MAX_UNPACK_TREES)
 		die("I cannot read more than %d trees", MAX_UNPACK_TREES);
-	tree = parse_tree_indirect(sha1);
+	tree = parse_tree_indirect(oid);
 	if (!tree)
 		return -1;
 	trees[nr_trees++] = tree;
@@ -96,12 +99,29 @@ static int debug_merge(const struct cache_entry * const *stages,
 	return 0;
 }
 
+static int option_parse_recurse_submodules(const struct option *opt,
+					   const char *arg, int unset)
+{
+	if (unset) {
+		recurse_submodules = RECURSE_SUBMODULES_OFF;
+		return 0;
+	}
+	if (arg)
+		recurse_submodules =
+			parse_update_recurse_submodules_arg(opt->long_name,
+							    arg);
+	else
+		recurse_submodules = RECURSE_SUBMODULES_ON;
+
+	return 0;
+}
+
 static struct lock_file lock_file;
 
 int cmd_read_tree(int argc, const char **argv, const char *unused_prefix)
 {
 	int i, stage = 0;
-	unsigned char sha1[20];
+	struct object_id oid;
 	struct tree_desc t[MAX_UNPACK_TREES];
 	struct unpack_trees_options opts;
 	int prefix_set = 0;
@@ -137,6 +157,9 @@ int cmd_read_tree(int argc, const char **argv, const char *unused_prefix)
 			 N_("skip applying sparse checkout filter")),
 		OPT_BOOL(0, "debug-unpack", &opts.debug_unpack,
 			 N_("debug unpack-trees")),
+		{ OPTION_CALLBACK, 0, "recurse-submodules", &recurse_submodules,
+			    "checkout", "control recursive updating of submodules",
+			    PARSE_OPT_OPTARG, option_parse_recurse_submodules },
 		OPT_END()
 	};
 
@@ -152,6 +175,12 @@ int cmd_read_tree(int argc, const char **argv, const char *unused_prefix)
 
 	hold_locked_index(&lock_file, LOCK_DIE_ON_ERROR);
 
+	if (recurse_submodules != RECURSE_SUBMODULES_DEFAULT) {
+		gitmodules_config();
+		git_config(submodule_config, NULL);
+		set_config_update_recurse_submodules(RECURSE_SUBMODULES_ON);
+	}
+
 	prefix_set = opts.prefix ? 1 : 0;
 	if (1 < opts.merge + opts.reset + prefix_set)
 		die("Which one? -m, --reset, or --prefix?");
@@ -175,13 +204,13 @@ int cmd_read_tree(int argc, const char **argv, const char *unused_prefix)
 	for (i = 0; i < argc; i++) {
 		const char *arg = argv[i];
 
-		if (get_sha1(arg, sha1))
+		if (get_oid(arg, &oid))
 			die("Not a valid object name %s", arg);
-		if (list_tree(sha1) < 0)
+		if (list_tree(&oid) < 0)
 			die("failed to unpack tree object %s", arg);
 		stage++;
 	}
-	if (nr_trees == 0 && !read_empty)
+	if (!nr_trees && !read_empty && !opts.merge)
 		warning("read-tree: emptying the index with no arguments is deprecated; use --empty");
 	else if (nr_trees > 0 && read_empty)
 		die("passing trees as arguments contradicts --empty");
@@ -197,9 +226,10 @@ int cmd_read_tree(int argc, const char **argv, const char *unused_prefix)
 		setup_work_tree();
 
 	if (opts.merge) {
-		if (stage < 2)
-			die("just how do you expect me to merge %d trees?", stage-1);
 		switch (stage - 1) {
+		case 0:
+			die("you must specify at least one tree to merge");
+			break;
 		case 1:
 			opts.fn = opts.prefix ? bind_merge : oneway_merge;
 			break;