thodg/libgit2

diff --git a/include/git2/submodule.h b/include/git2/submodule.h
index 186f263..a150759 100644
--- a/include/git2/submodule.h
+++ b/include/git2/submodule.h
@@ -105,6 +105,19 @@ typedef enum {
 	GIT_SUBMODULE_STATUS_WD_UNTRACKED)) != 0)
 
 /**
+ * Options for submodule recurse.
+ *
+ * * GIT_SUBMODULE_RECURSE_NO   - do no recurse into submodules
+ * * GIT_SUBMODULE_RECURSE_YES  - recurse into submodules
+ * * GIT_SUBMODULE_RECURSE_ONDEMAND - recurse into submodules only when commit not already in local clone
+ */
+typedef enum {
+	GIT_SUBMODULE_RECURSE_NO = 0,
+	GIT_SUBMODULE_RECURSE_YES = 1,
+	GIT_SUBMODULE_RECURSE_ONDEMAND = 2,
+} git_submodule_recurse_t;
+
+/**
  * Lookup submodule information by name or path.
  *
  * Given either the submodule name or path (they are usually the same), this
@@ -410,7 +423,7 @@ GIT_EXTERN(git_submodule_update_t) git_submodule_set_update(
  *
  * @return 0 if fetchRecurseSubmodules is false, 1 if true
  */
-GIT_EXTERN(int) git_submodule_fetch_recurse_submodules(
+GIT_EXTERN(git_submodule_recurse_t) git_submodule_fetch_recurse_submodules(
 	git_submodule *submodule);
 
 /**
@@ -426,7 +439,7 @@ GIT_EXTERN(int) git_submodule_fetch_recurse_submodules(
  */
 GIT_EXTERN(int) git_submodule_set_fetch_recurse_submodules(
 	git_submodule *submodule,
-	int fetch_recurse_submodules);
+	git_submodule_recurse_t fetch_recurse_submodules);
 
 /**
  * Copy submodule info into ".git/config" file.
diff --git a/src/submodule.c b/src/submodule.c
index f6660a8..5548e45 100644
--- a/src/submodule.c
+++ b/src/submodule.c
@@ -43,6 +43,12 @@ static git_cvar_map _sm_ignore_map[] = {
 	{GIT_CVAR_TRUE, NULL, GIT_SUBMODULE_IGNORE_ALL},
 };
 
+static git_cvar_map _sm_recurse_map[] = {
+	{GIT_CVAR_STRING, "on-demand", GIT_SUBMODULE_RECURSE_ONDEMAND},
+	{GIT_CVAR_FALSE, NULL, GIT_SUBMODULE_RECURSE_NO},
+	{GIT_CVAR_TRUE, NULL, GIT_SUBMODULE_RECURSE_YES},
+};
+
 static kh_inline khint_t str_hash_no_trailing_slash(const char *s)
 {
 	khint_t h;
@@ -428,6 +434,15 @@ const char *git_submodule_update_to_str(git_submodule_update_t update)
 	return NULL;
 }
 
+const char *git_submodule_recurse_to_str(git_submodule_recurse_t recurse)
+{
+	int i;
+	for (i = 0; i < (int)ARRAY_SIZE(_sm_recurse_map); ++i)
+		if (_sm_recurse_map[i].map_value == recurse)
+			return _sm_recurse_map[i].str_match;
+	return NULL;
+}
+
 int git_submodule_save(git_submodule *submodule)
 {
 	int error = 0;
@@ -469,10 +484,10 @@ int git_submodule_save(git_submodule *submodule)
 	if (error < 0)
 		goto cleanup;
 
-	if ((error = submodule_config_key_trunc_puts(
-			&key, "fetchRecurseSubmodules")) < 0 ||
-		(error = git_config_file_set_string(
-			mods, key.ptr, submodule->fetch_recurse ? "true" : "false")) < 0)
+	if (!(error = submodule_config_key_trunc_puts(&key, "fetchRecurseSubmodules")) &&
+		(val = git_submodule_recurse_to_str(submodule->fetch_recurse)) != NULL)
+		error = git_config_file_set_string(mods, key.ptr, val);
+	if (error < 0)
 		goto cleanup;
 
 	/* update internal defaults */
@@ -610,7 +625,7 @@ git_submodule_update_t git_submodule_set_update(
 	return old;
 }
 
-int git_submodule_fetch_recurse_submodules(
+git_submodule_recurse_t git_submodule_fetch_recurse_submodules(
 	git_submodule *submodule)
 {
 	assert(submodule);
@@ -619,14 +634,14 @@ int git_submodule_fetch_recurse_submodules(
 
 int git_submodule_set_fetch_recurse_submodules(
 	git_submodule *submodule,
-	int fetch_recurse_submodules)
+	git_submodule_recurse_t fetch_recurse_submodules)
 {
 	int old;
 
 	assert(submodule);
 
 	old = submodule->fetch_recurse;
-	submodule->fetch_recurse = (fetch_recurse_submodules != 0);
+	submodule->fetch_recurse = fetch_recurse_submodules;
 	return old;
 }
 
@@ -975,6 +990,7 @@ static git_submodule *submodule_alloc(git_repository *repo, const char *name)
 	GIT_REFCOUNT_INC(sm);
 	sm->ignore = sm->ignore_default = GIT_SUBMODULE_IGNORE_NONE;
 	sm->update = sm->update_default = GIT_SUBMODULE_UPDATE_CHECKOUT;
+	sm->fetch_recurse = sm->update_default = GIT_SUBMODULE_RECURSE_YES;
 	sm->repo   = repo;
 
 	return sm;
@@ -1080,6 +1096,20 @@ int git_submodule_parse_update(git_submodule_update_t *out, const char *value)
 	return 0;
 }
 
+int git_submodule_parse_recurse(git_submodule_recurse_t *out, const char *value)
+{
+	int val;
+
+	if (git_config_lookup_map_value(
+			&val, _sm_recurse_map, ARRAY_SIZE(_sm_recurse_map), value) < 0) {
+		*out = GIT_SUBMODULE_RECURSE_YES;
+		return submodule_config_error("recurse", value);
+	}
+
+	*out = (git_submodule_recurse_t)val;
+	return 0;
+}
+
 static int submodule_load_from_config(
 	const git_config_entry *entry, void *payload)
 {
@@ -1166,10 +1196,8 @@ static int submodule_load_from_config(
 		sm->update_default = sm->update;
 	}
 	else if (strcasecmp(property, "fetchRecurseSubmodules") == 0) {
-		if (git__parse_bool(&sm->fetch_recurse, value) < 0) {
-			error = submodule_config_error("fetchRecurseSubmodules", value);
-			goto done;
-		}
+		if (git_submodule_parse_recurse(&sm->fetch_recurse, value) < 0)
+			return -1;
 	}
 	else if (strcasecmp(property, "ignore") == 0) {
 		if ((error = git_submodule_parse_ignore(&sm->ignore, value)) < 0)
diff --git a/src/submodule.h b/src/submodule.h
index b059375..2a610e1 100644
--- a/src/submodule.h
+++ b/src/submodule.h
@@ -85,7 +85,7 @@ struct git_submodule {
 	git_submodule_update_t update_default;
 	git_submodule_ignore_t ignore;
 	git_submodule_ignore_t ignore_default;
-	int fetch_recurse;
+	git_submodule_recurse_t fetch_recurse;
 
 	/* internal information */
 	git_repository *repo;
diff --git a/tests/submodule/modify.c b/tests/submodule/modify.c
index e326287..8ec9fce 100644
--- a/tests/submodule/modify.c
+++ b/tests/submodule/modify.c
@@ -168,7 +168,7 @@ void test_submodule_modify__edit_and_save(void)
 	git_submodule_ignore_t old_ignore;
 	git_submodule_update_t old_update;
 	git_repository *r2;
-	int old_fetchrecurse;
+	git_submodule_recurse_t old_fetchrecurse;
 
 	cl_git_pass(git_submodule_lookup(&sm1, g_repo, "sm_changed_head"));
 
@@ -178,14 +178,14 @@ void test_submodule_modify__edit_and_save(void)
 	cl_git_pass(git_submodule_set_url(sm1, SM_LIBGIT2_URL));
 	old_ignore = git_submodule_set_ignore(sm1, GIT_SUBMODULE_IGNORE_UNTRACKED);
 	old_update = git_submodule_set_update(sm1, GIT_SUBMODULE_UPDATE_REBASE);
-	old_fetchrecurse = git_submodule_set_fetch_recurse_submodules(sm1, 1);
+	old_fetchrecurse = git_submodule_set_fetch_recurse_submodules(sm1, GIT_SUBMODULE_RECURSE_YES);
 
 	cl_assert_equal_s(SM_LIBGIT2_URL, git_submodule_url(sm1));
 	cl_assert_equal_i(
 		(int)GIT_SUBMODULE_IGNORE_UNTRACKED, (int)git_submodule_ignore(sm1));
 	cl_assert_equal_i(
 		(int)GIT_SUBMODULE_UPDATE_REBASE, (int)git_submodule_update(sm1));
-	cl_assert_equal_i(1, git_submodule_fetch_recurse_submodules(sm1));
+	cl_assert_equal_i(GIT_SUBMODULE_RECURSE_YES, git_submodule_fetch_recurse_submodules(sm1));
 
 	/* revert without saving (and confirm setters return old value) */
 	cl_git_pass(git_submodule_set_url(sm1, old_url));
@@ -196,7 +196,7 @@ void test_submodule_modify__edit_and_save(void)
 		(int)GIT_SUBMODULE_UPDATE_REBASE,
 		(int)git_submodule_set_update(sm1, GIT_SUBMODULE_UPDATE_RESET));
 	cl_assert_equal_i(
-		1, git_submodule_set_fetch_recurse_submodules(sm1, old_fetchrecurse));
+		GIT_SUBMODULE_RECURSE_YES, git_submodule_set_fetch_recurse_submodules(sm1, old_fetchrecurse));
 
 	/* check that revert was successful */
 	cl_assert_equal_s(old_url, git_submodule_url(sm1));
@@ -209,7 +209,7 @@ void test_submodule_modify__edit_and_save(void)
 	cl_git_pass(git_submodule_set_url(sm1, SM_LIBGIT2_URL));
 	git_submodule_set_ignore(sm1, GIT_SUBMODULE_IGNORE_UNTRACKED);
 	git_submodule_set_update(sm1, GIT_SUBMODULE_UPDATE_REBASE);
-	git_submodule_set_fetch_recurse_submodules(sm1, 1);
+	git_submodule_set_fetch_recurse_submodules(sm1, GIT_SUBMODULE_RECURSE_YES);
 
 	/* call save */
 	cl_git_pass(git_submodule_save(sm1));
@@ -225,7 +225,7 @@ void test_submodule_modify__edit_and_save(void)
 		(int)GIT_SUBMODULE_IGNORE_UNTRACKED, (int)git_submodule_ignore(sm1));
 	cl_assert_equal_i(
 		(int)GIT_SUBMODULE_UPDATE_REBASE, (int)git_submodule_update(sm1));
-	cl_assert_equal_i(1, git_submodule_fetch_recurse_submodules(sm1));
+	cl_assert_equal_i(GIT_SUBMODULE_RECURSE_YES, git_submodule_fetch_recurse_submodules(sm1));
 
 	/* call reload and check that the new values are loaded */
 	cl_git_pass(git_submodule_reload(sm1));
@@ -235,7 +235,7 @@ void test_submodule_modify__edit_and_save(void)
 		(int)GIT_SUBMODULE_IGNORE_UNTRACKED, (int)git_submodule_ignore(sm1));
 	cl_assert_equal_i(
 		(int)GIT_SUBMODULE_UPDATE_REBASE, (int)git_submodule_update(sm1));
-	cl_assert_equal_i(1, git_submodule_fetch_recurse_submodules(sm1));
+	cl_assert_equal_i(GIT_SUBMODULE_RECURSE_YES, git_submodule_fetch_recurse_submodules(sm1));
 
 	/* open a second copy of the repo and compare submodule */
 	cl_git_pass(git_repository_open(&r2, "submod2"));
@@ -246,7 +246,16 @@ void test_submodule_modify__edit_and_save(void)
 		(int)GIT_SUBMODULE_IGNORE_UNTRACKED, (int)git_submodule_ignore(sm2));
 	cl_assert_equal_i(
 		(int)GIT_SUBMODULE_UPDATE_REBASE, (int)git_submodule_update(sm2));
-	cl_assert_equal_i(1, git_submodule_fetch_recurse_submodules(sm2));
+	cl_assert_equal_i(GIT_SUBMODULE_RECURSE_YES, git_submodule_fetch_recurse_submodules(sm2));
+
+	/* set fetchRecurseSubmodules on-demand */
+	cl_git_pass(git_submodule_reload(sm1));
+	git_submodule_set_fetch_recurse_submodules(sm1, GIT_SUBMODULE_RECURSE_ONDEMAND);
+	cl_assert_equal_i(GIT_SUBMODULE_RECURSE_ONDEMAND, git_submodule_fetch_recurse_submodules(sm1));
+	/* call save */
+	cl_git_pass(git_submodule_save(sm1));
+	cl_git_pass(git_submodule_reload(sm1));
+	cl_assert_equal_i(GIT_SUBMODULE_RECURSE_ONDEMAND, git_submodule_fetch_recurse_submodules(sm1));
 
 	git_repository_free(r2);
 	git__free(old_url);