clone: set submodule.recurse=true if submodule.stickyRecursiveClone enabled

Based on current experience, when running git clone --recurse-submodules,
developers do not expect other commands such as pull or checkout to run
recursively into active submodules. However, setting submodule.recurse=true
at this step could make for a simpler workflow by eliminating the need for
the --recurse-submodules option in subsequent commands. To collect more
data on developers' preference in regards to making submodule.recurse=true
a default config value in the future, deploy this feature under the opt in
submodule.stickyRecursiveClone flag.

Signed-off-by: Mahi Kolla <mkolla2@illinois.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

builtin/clone.c

@@ -1114,6 +1114,7 @@ int cmd_clone(int argc, const char **argv, const char *prefix)
 	if (option_recurse_submodules.nr > 0) {
 		struct string_list_item *item;
 		struct strbuf sb = STRBUF_INIT;
+		int val;
 
 		/* remove duplicates */
 		string_list_sort(&option_recurse_submodules);
@@ -1130,6 +1131,10 @@ int cmd_clone(int argc, const char **argv, const char *prefix)
 					   strbuf_detach(&sb, NULL));
 		}
 
+		if (!git_config_get_bool("submodule.stickyRecursiveClone", &val) &&
+		    val)
+			string_list_append(&option_config, "submodule.recurse=true");
+
 		if (option_required_reference.nr &&
 		    option_optional_reference.nr)
 			die(_("clone --recursive is not compatible with "

t/t5606-clone-options.sh

@@ -16,6 +16,18 @@ test_expect_success 'setup' '
 
 '
 
+test_expect_success 'submodule.stickyRecursiveClone flag manipulates submodule.recurse value' '
+
+	test_config_global submodule.stickyRecursiveClone true &&
+	git clone --recurse-submodules parent clone_recurse_true &&
+	test_cmp_config -C clone_recurse_true true submodule.recurse &&
+
+	test_config_global submodule.stickyRecursiveClone false &&
+	git clone --recurse-submodules parent clone_recurse_false &&
+	test_expect_code 1 git -C clone_recurse_false config --get submodule.recurse
+
+'
+
 test_expect_success 'clone -o' '
 
 	git clone -o foo parent clone-o &&