1 files changed, 52 insertions, 12 deletions

diff --git a/builtin/submodule--helper.c b/builtin/submodule--helper.c
index 521b4b3aa8..1a4b391c88 100644
--- a/builtin/submodule--helper.c
+++ b/builtin/submodule--helper.c
@@ -20,6 +20,7 @@
 #include "diff.h"
 #include "object-store.h"
 #include "dir.h"
+#include "advice.h"
 
 #define OPT_QUIET (1 << 0)
 #define OPT_CACHED (1 << 1)
@@ -443,19 +444,19 @@ static void for_each_listed_submodule(const struct module_list *list,
 		fn(list->entries[i], cb_data);
 }
 
-struct cb_foreach {
+struct foreach_cb {
 	int argc;
 	const char **argv;
 	const char *prefix;
 	int quiet;
 	int recursive;
 };
-#define CB_FOREACH_INIT { 0 }
+#define FOREACH_CB_INIT { 0 }
 
 static void runcommand_in_submodule_cb(const struct cache_entry *list_item,
 				       void *cb_data)
 {
-	struct cb_foreach *info = cb_data;
+	struct foreach_cb *info = cb_data;
 	const char *path = list_item->name;
 	const struct object_id *ce_oid = &list_item->oid;
 
@@ -556,7 +557,7 @@ cleanup:
 
 static int module_foreach(int argc, const char **argv, const char *prefix)
 {
-	struct cb_foreach info = CB_FOREACH_INIT;
+	struct foreach_cb info = FOREACH_CB_INIT;
 	struct pathspec pathspec;
 	struct module_list list = MODULE_LIST_INIT;
 
@@ -781,6 +782,8 @@ static void status_submodule(const char *path, const struct object_id *ce_oid,
 	struct argv_array diff_files_args = ARGV_ARRAY_INIT;
 	struct rev_info rev;
 	int diff_files_result;
+	struct strbuf buf = STRBUF_INIT;
+	const char *git_dir;
 
 	if (!submodule_from_path(the_repository, &null_oid, path))
 		die(_("no submodule mapping found in .gitmodules for path '%s'"),
@@ -793,17 +796,26 @@ static void status_submodule(const char *path, const struct object_id *ce_oid,
 		goto cleanup;
 	}
 
-	if (!is_submodule_active(the_repository, path)) {
+	strbuf_addf(&buf, "%s/.git", path);
+	git_dir = read_gitfile(buf.buf);
+	if (!git_dir)
+		git_dir = buf.buf;
+
+	if (!is_submodule_active(the_repository, path) ||
+	    !is_git_directory(git_dir)) {
 		print_status(flags, '-', path, ce_oid, displaypath);
+		strbuf_release(&buf);
 		goto cleanup;
 	}
+	strbuf_release(&buf);
 
 	argv_array_pushl(&diff_files_args, "diff-files",
 			 "--ignore-submodules=dirty", "--quiet", "--",
 			 path, NULL);
 
 	git_config(git_diff_basic_config, NULL);
-	repo_init_revisions(the_repository, &rev, prefix);
+
+	repo_init_revisions(the_repository, &rev, NULL);
 	rev.abbrev = 0;
 	diff_files_args.argc = setup_revisions(diff_files_args.argc,
 					       diff_files_args.argv,
@@ -1223,7 +1235,7 @@ static int module_deinit(int argc, const char **argv, const char *prefix)
 
 static int clone_submodule(const char *path, const char *gitdir, const char *url,
 			   const char *depth, struct string_list *reference, int dissociate,
-			   int quiet, int progress)
+			   int quiet, int progress, int single_branch)
 {
 	struct child_process cp = CHILD_PROCESS_INIT;
 
@@ -1245,6 +1257,10 @@ static int clone_submodule(const char *path, const char *gitdir, const char *url
 		argv_array_push(&cp.args, "--dissociate");
 	if (gitdir && *gitdir)
 		argv_array_pushl(&cp.args, "--separate-git-dir", gitdir, NULL);
+	if (single_branch >= 0)
+		argv_array_push(&cp.args, single_branch ?
+					  "--single-branch" :
+					  "--no-single-branch");
 
 	argv_array_push(&cp.args, "--");
 	argv_array_push(&cp.args, url);
@@ -1269,6 +1285,13 @@ struct submodule_alternate_setup {
 #define SUBMODULE_ALTERNATE_SETUP_INIT { NULL, \
 	SUBMODULE_ALTERNATE_ERROR_IGNORE, NULL }
 
+static const char alternate_error_advice[] = N_(
+"An alternate computed from a superproject's alternate is invalid.\n"
+"To allow Git to clone without an alternate in such a case, set\n"
+"submodule.alternateErrorStrategy to 'info' or, equivalently, clone with\n"
+"'--reference-if-able' instead of '--reference'."
+);
+
 static int add_possible_reference_from_superproject(
 		struct object_directory *odb, void *sas_cb)
 {
@@ -1300,6 +1323,8 @@ static int add_possible_reference_from_superproject(
 		} else {
 			switch (sas->error_mode) {
 			case SUBMODULE_ALTERNATE_ERROR_DIE:
+				if (advice_submodule_alternate_error_strategy_die)
+					advise(_(alternate_error_advice));
 				die(_("submodule '%s' cannot add alternate: %s"),
 				    sas->submodule_name, err.buf);
 			case SUBMODULE_ALTERNATE_ERROR_INFO:
@@ -1362,6 +1387,7 @@ static int module_clone(int argc, const char **argv, const char *prefix)
 	struct string_list reference = STRING_LIST_INIT_NODUP;
 	int dissociate = 0, require_init = 0;
 	char *sm_alternate = NULL, *error_strategy = NULL;
+	int single_branch = -1;
 
 	struct option module_clone_options[] = {
 		OPT_STRING(0, "prefix", &prefix,
@@ -1389,12 +1415,15 @@ static int module_clone(int argc, const char **argv, const char *prefix)
 			   N_("force cloning progress")),
 		OPT_BOOL(0, "require-init", &require_init,
 			   N_("disallow cloning into non-empty directory")),
+		OPT_BOOL(0, "single-branch", &single_branch,
+			 N_("clone only one branch, HEAD or --branch")),
 		OPT_END()
 	};
 
 	const char *const git_submodule_helper_usage[] = {
 		N_("git submodule--helper clone [--prefix=<path>] [--quiet] "
 		   "[--reference <repository>] [--name <name>] [--depth <depth>] "
+		   "[--single-branch] "
 		   "--url <url> --path <path>"),
 		NULL
 	};
@@ -1427,7 +1456,7 @@ static int module_clone(int argc, const char **argv, const char *prefix)
 		prepare_possible_alternates(name, &reference);
 
 		if (clone_submodule(path, sm_gitdir, url, depth, &reference, dissociate,
-				    quiet, progress))
+				    quiet, progress, single_branch))
 			die(_("clone of '%s' into submodule path '%s' failed"),
 			    url, path);
 	} else {
@@ -1551,6 +1580,7 @@ struct submodule_update_clone {
 	const char *depth;
 	const char *recursive_prefix;
 	const char *prefix;
+	int single_branch;
 
 	/* to be consumed by git-submodule.sh */
 	struct update_clone_data *update_clone;
@@ -1565,10 +1595,14 @@ struct submodule_update_clone {
 
 	int max_jobs;
 };
-#define SUBMODULE_UPDATE_CLONE_INIT {0, MODULE_LIST_INIT, 0, \
-	SUBMODULE_UPDATE_STRATEGY_INIT, 0, 0, -1, STRING_LIST_INIT_DUP, 0, 0, \
-	NULL, NULL, NULL, \
-	NULL, 0, 0, 0, NULL, 0, 0, 1}
+#define SUBMODULE_UPDATE_CLONE_INIT { \
+	.list = MODULE_LIST_INIT, \
+	.update = SUBMODULE_UPDATE_STRATEGY_INIT, \
+	.recommend_shallow = -1, \
+	.references = STRING_LIST_INIT_DUP, \
+	.single_branch = -1, \
+	.max_jobs = 1, \
+}
 
 
 static void next_submodule_warn_missing(struct submodule_update_clone *suc,
@@ -1707,6 +1741,10 @@ static int prepare_to_clone_next_submodule(const struct cache_entry *ce,
 		argv_array_push(&child->args, "--dissociate");
 	if (suc->depth)
 		argv_array_push(&child->args, suc->depth);
+	if (suc->single_branch >= 0)
+		argv_array_push(&child->args, suc->single_branch ?
+					      "--single-branch" :
+					      "--no-single-branch");
 
 cleanup:
 	strbuf_reset(&displaypath_sb);
@@ -1886,6 +1924,8 @@ static int update_clone(int argc, const char **argv, const char *prefix)
 			    N_("force cloning progress")),
 		OPT_BOOL(0, "require-init", &suc.require_init,
 			   N_("disallow cloning into non-empty directory")),
+		OPT_BOOL(0, "single-branch", &suc.single_branch,
+			 N_("clone only one branch, HEAD or --branch")),
 		OPT_END()
 	};