pull: honor submodule.recurse config option

"git pull" supports a --recurse-submodules option but does not parse the
submodule.recurse configuration item to set the default for that option.
Meanwhile "git fetch" does support submodule.recurse, producing
confusing behavior: when submodule.recurse is enabled, "git pull"
recursively fetches submodules but does not update them after fetch.

Handle submodule.recurse in "git pull" to fix this.

Reported-by: Magnus Homann <magnus@homann.se>
Signed-off-by: Nicolas Morey-Chaisemartin <nicolas@morey-chaisemartin.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

builtin/pull.c

@@ -325,6 +325,10 @@ static int git_pull_config(const char *var, const char *value, void *cb)
 	if (!strcmp(var, "rebase.autostash")) {
 		config_autostash = git_config_bool(var, value);
 		return 0;
+	} else if (!strcmp(var, "submodule.recurse")) {
+		recurse_submodules = git_config_bool(var, value) ?
+			RECURSE_SUBMODULES_ON : RECURSE_SUBMODULES_OFF;
+		return 0;
 	}
 	return git_default_config(var, value, cb);
 }

t/t5572-pull-submodule.sh

@@ -65,6 +65,38 @@ test_expect_success 'recursive pull updates working tree' '
 	test_path_is_file super/sub/merge_strategy.t
 '
 
+test_expect_success "submodule.recurse option triggers recursive pull" '
+	test_commit -C child merge_strategy_2 &&
+	git -C parent submodule update --remote &&
+	git -C parent add sub &&
+	git -C parent commit -m "update submodule" &&
+
+	git -C super -c submodule.recurse pull --no-rebase &&
+	test_path_is_file super/sub/merge_strategy_2.t
+'
+
+test_expect_success " --[no-]recurse-submodule and submodule.recurse" '
+	test_commit -C child merge_strategy_3 &&
+	git -C parent submodule update --remote &&
+	git -C parent add sub &&
+	git -C parent commit -m "update submodule" &&
+
+	git -C super -c submodule.recurse pull --no-recurse-submodules --no-rebase &&
+	test_path_is_missing super/sub/merge_strategy_3.t &&
+	git -C super -c submodule.recurse=false pull --recurse-submodules --no-rebase &&
+	test_path_is_file super/sub/merge_strategy_3.t &&
+
+	test_commit -C child merge_strategy_4 &&
+	git -C parent submodule update --remote &&
+	git -C parent add sub &&
+	git -C parent commit -m "update submodule" &&
+
+	git -C super -c submodule.recurse=false pull --no-recurse-submodules --no-rebase &&
+	test_path_is_missing super/sub/merge_strategy_4.t &&
+	git -C super -c submodule.recurse=true pull --recurse-submodules --no-rebase &&
+	test_path_is_file super/sub/merge_strategy_4.t
+'
+
 test_expect_success 'recursive rebasing pull' '
 	# change upstream
 	test_commit -C child rebase_strategy &&