Merge branch 'sb/checkout-recurse-submodules'

"git checkout" is taught the "--recurse-submodules" option.

* sb/checkout-recurse-submodules:
  builtin/read-tree: add --recurse-submodules switch
  builtin/checkout: add --recurse-submodules switch
  entry.c: create submodules when interesting
  unpack-trees: check if we can perform the operation for submodules
  unpack-trees: pass old oid to verify_clean_submodule
  update submodules: add submodule_move_head
  submodule.c: get_super_prefix_or_empty
  update submodules: move up prepare_submodule_repo_env
  submodules: introduce check to see whether to touch a submodule
  update submodules: add a config option to determine if submodules are updated
  update submodules: add submodule config parsing
  make is_submodule_populated gently
  lib-submodule-update.sh: define tests for recursing into submodules
  lib-submodule-update.sh: replace sha1 by hash
  lib-submodule-update: teach test_submodule_content the -C <dir> flag
  lib-submodule-update.sh: do not use ./. as submodule remote
  lib-submodule-update.sh: reorder create_lib_submodule_repo
  submodule--helper.c: remove duplicate code
  connect_work_tree_and_git_dir: safely create leading directories

4 files changed, 60 insertions, 21 deletions

diff --git a/builtin/checkout.c b/builtin/checkout.c
index 81f07c3ef2..3ecc47bec0 100644
--- a/builtin/checkout.c
+++ b/builtin/checkout.c
@@ -21,12 +21,31 @@
 #include "submodule-config.h"
 #include "submodule.h"
 
+static int recurse_submodules = RECURSE_SUBMODULES_DEFAULT;
+
 static const char * const checkout_usage[] = {
 	N_("git checkout [<options>] <branch>"),
 	N_("git checkout [<options>] [<branch>] -- <file>..."),
 	NULL,
 };
 
+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;
+}
+
 struct checkout_opts {
 	int patch_mode;
 	int quiet;
@@ -1163,6 +1182,9 @@ int cmd_checkout(int argc, const char **argv, const char *prefix)
 				N_("second guess 'git checkout <no-such-branch>'")),
 		OPT_BOOL(0, "ignore-other-worktrees", &opts.ignore_other_worktrees,
 			 N_("do not check if another worktree is holding the given ref")),
+		{ OPTION_CALLBACK, 0, "recurse-submodules", &recurse_submodules,
+			    "checkout", "control recursive updating of submodules",
+			    PARSE_OPT_OPTARG, option_parse_recurse_submodules },
 		OPT_BOOL(0, "progress", &opts.show_progress, N_("force progress reporting")),
 		OPT_END(),
 	};
@@ -1193,6 +1215,12 @@ int cmd_checkout(int argc, const char **argv, const char *prefix)
 		git_xmerge_config("merge.conflictstyle", conflict_style, NULL);
 	}
 
+	if (recurse_submodules != RECURSE_SUBMODULES_OFF) {
+		git_config(submodule_config, NULL);
+		if (recurse_submodules != RECURSE_SUBMODULES_DEFAULT)
+			set_config_update_recurse_submodules(recurse_submodules);
+	}
+
 	if ((!!opts.new_branch + !!opts.new_branch_force + !!opts.new_orphan_branch) > 1)
 		die(_("-b, -B and --orphan are mutually exclusive"));
 
diff --git a/builtin/grep.c b/builtin/grep.c
index a9e82dc975..3f3efa95de 100644
--- a/builtin/grep.c
+++ b/builtin/grep.c
@@ -618,7 +618,7 @@ static int grep_submodule(struct grep_opt *opt, const unsigned char *sha1,
 {
 	if (!is_submodule_initialized(path))
 		return 0;
-	if (!is_submodule_populated(path)) {
+	if (!is_submodule_populated_gently(path, NULL)) {
 		/*
 		 * If searching history, check for the presense of the
 		 * submodule's gitdir before skipping the submodule.
diff --git a/builtin/read-tree.c b/builtin/read-tree.c
index 8ba64bc785..23e212ee8c 100644
--- a/builtin/read-tree.c
+++ b/builtin/read-tree.c
@@ -15,10 +15,13 @@
 #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)
 {
@@ -96,6 +99,23 @@ 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)
@@ -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?");
diff --git a/builtin/submodule--helper.c b/builtin/submodule--helper.c
index 15a5430c00..be316bbbc8 100644
--- a/builtin/submodule--helper.c
+++ b/builtin/submodule--helper.c
@@ -577,9 +577,7 @@ static int module_clone(int argc, const char **argv, const char *prefix)
 	const char *name = NULL, *url = NULL, *depth = NULL;
 	int quiet = 0;
 	int progress = 0;
-	FILE *submodule_dot_git;
 	char *p, *path = NULL, *sm_gitdir;
-	struct strbuf rel_path = STRBUF_INIT;
 	struct strbuf sb = STRBUF_INIT;
 	struct string_list reference = STRING_LIST_INIT_NODUP;
 	char *sm_alternate = NULL, *error_strategy = NULL;
@@ -651,27 +649,12 @@ static int module_clone(int argc, const char **argv, const char *prefix)
 		strbuf_reset(&sb);
 	}
 
-	/* Write a .git file in the submodule to redirect to the superproject. */
-	strbuf_addf(&sb, "%s/.git", path);
-	if (safe_create_leading_directories_const(sb.buf) < 0)
-		die(_("could not create leading directories of '%s'"), sb.buf);
-	submodule_dot_git = fopen(sb.buf, "w");
-	if (!submodule_dot_git)
-		die_errno(_("cannot open file '%s'"), sb.buf);
-
-	fprintf_or_die(submodule_dot_git, "gitdir: %s\n",
-		       relative_path(sm_gitdir, path, &rel_path));
-	if (fclose(submodule_dot_git))
-		die(_("could not close file %s"), sb.buf);
-	strbuf_reset(&sb);
-	strbuf_reset(&rel_path);
+	/* Connect module worktree and git dir */
+	connect_work_tree_and_git_dir(path, sm_gitdir);
 
-	/* Redirect the worktree of the submodule in the superproject's config */
 	p = git_pathdup_submodule(path, "config");
 	if (!p)
 		die(_("could not get submodule directory for '%s'"), path);
-	git_config_set_in_file(p, "core.worktree",
-			       relative_path(path, sm_gitdir, &rel_path));
 
 	/* setup alternateLocation and alternateErrorStrategy in the cloned submodule if needed */
 	git_config_get_string("submodule.alternateLocation", &sm_alternate);
@@ -687,7 +670,6 @@ static int module_clone(int argc, const char **argv, const char *prefix)
 	free(error_strategy);
 
 	strbuf_release(&sb);
-	strbuf_release(&rel_path);
 	free(sm_gitdir);
 	free(path);
 	free(p);