Submodules: Add 'on-demand' value for the 'fetchRecurseSubmodule' option

Now the behavior of fetch and pull can be configured to the recently added
'on-demand' mode separately for each submodule too.

Signed-off-by: Jens Lehmann <Jens.Lehmann@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Documentation/config.txt

@@ -1823,7 +1823,7 @@ submodule.<name>.update::
 	linkgit:git-submodule[1] and linkgit:gitmodules[5] for details.
 
 submodule.<name>.fetchRecurseSubmodules::
-	This option can be used to enable/disable recursive fetching of this
+	This option can be used to control recursive fetching of this
 	submodule. It can be overridden by using the --[no-]recurse-submodules
 	command line option to "git fetch" and "git pull".
 	This setting will override that from in the linkgit:gitmodules[5]

Documentation/gitmodules.txt

@@ -45,12 +45,12 @@ submodule.<name>.update::
 	the '--merge' or '--rebase' options.
 
 submodule.<name>.fetchRecurseSubmodules::
-	This option can be used to enable/disable recursive fetching of this
+	This option can be used to control recursive fetching of this
 	submodule. If this option is also present in the submodules entry in
 	.git/config of the superproject, the setting there will override the
 	one found in .gitmodules.
 	Both settings can be overridden on the command line by using the
-	"--[no-]recurse-submodules" option to "git fetch" and "git pull"..
+	"--[no-]recurse-submodules" option to "git fetch" and "git pull".
 
 submodule.<name>.ignore::
 	Defines under what circumstances "git status" and the diff family show

submodule.c

@@ -113,7 +113,7 @@ int parse_submodule_config_option(const char *var, const char *value)
 		if (!config)
 			config = string_list_append(&config_fetch_recurse_submodules_for_name,
 						    strbuf_detach(&submodname, NULL));
-		config->util = git_config_bool(var, value) ? (void *)1 : NULL;
+		config->util = (void *)(intptr_t)parse_fetch_recurse_submodules_arg(var, value);
 		strbuf_release(&submodname);
 	} else if ((len > 7) && !strcmp(var + len - 7, ".ignore")) {
 		if (strcmp(value, "untracked") && strcmp(value, "dirty") &&
@@ -380,8 +380,13 @@ int fetch_populated_submodules(int num_options, const char **options,
 			struct string_list_item *fetch_recurse_submodules_option;
 			fetch_recurse_submodules_option = unsorted_string_list_lookup(&config_fetch_recurse_submodules_for_name, name);
 			if (fetch_recurse_submodules_option) {
-				if (!fetch_recurse_submodules_option->util)
+				if ((intptr_t)fetch_recurse_submodules_option->util == RECURSE_SUBMODULES_OFF)
 					continue;
+				if ((intptr_t)fetch_recurse_submodules_option->util == RECURSE_SUBMODULES_ON_DEMAND) {
+					if (!unsorted_string_list_lookup(&changed_submodule_paths, ce->name))
+						continue;
+					default_argv = "on-demand";
+				}
 			} else {
 				if (config_fetch_recurse_submodules == RECURSE_SUBMODULES_OFF)
 					continue;

t/t5526-fetch-submodules.sh

@@ -400,4 +400,32 @@ test_expect_success "'fetch.recurseSubmodules=on-demand' overrides global config
 	test_cmp expect.err.2 actual.err
 '
 
+test_expect_success "'submodule.<sub>.fetchRecurseSubmodules=on-demand' overrides fetch.recurseSubmodules" '
+	(
+		cd downstream &&
+		git fetch --recurse-submodules
+	) &&
+	add_upstream_commit &&
+	git config fetch.recurseSubmodules false &&
+	head1=$(git rev-parse --short HEAD) &&
+	git add submodule &&
+	git commit -m "new submodule" &&
+	head2=$(git rev-parse --short HEAD) &&
+	echo "From $pwd/." > expect.err.2 &&
+	echo "   $head1..$head2  master     -> origin/master" >> expect.err.2
+	head -2 expect.err >> expect.err.2 &&
+	(
+		cd downstream &&
+		git config submodule.submodule.fetchRecurseSubmodules on-demand &&
+		git fetch >../actual.out 2>../actual.err
+	) &&
+	git config --unset fetch.recurseSubmodules &&
+	(
+		cd downstream &&
+		git config --unset submodule.submodule.fetchRecurseSubmodules
+	) &&
+	test_cmp expect.out.sub actual.out &&
+	test_cmp expect.err.2 actual.err
+'
+
 test_done