submodule update: respect depth in subsequent fetches

When depth is given the user may have a reasonable expectation that
any remote operation is using the given depth. Add a test to demonstrate
we still get the desired sha1 even if the depth is too short to
include the actual commit.

Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

git-submodule.sh

@@ -479,7 +479,8 @@ fetch_in_submodule () (
 	'')
 		git fetch ;;
 	*)
-		git fetch $(get_default_remote) "$2" ;;
+		shift
+		git fetch $(get_default_remote) "$@" ;;
 	esac
 )
 
@@ -617,7 +618,7 @@ cmd_update()
 			if test -z "$nofetch"
 			then
 				# Fetch remote before determining tracking $sha1
-				fetch_in_submodule "$sm_path" ||
+				fetch_in_submodule "$sm_path" $depth ||
 				die "$(eval_gettext "Unable to fetch in submodule path '\$sm_path'")"
 			fi
 			remote_name=$(sanitize_submodule_env; cd "$sm_path" && get_default_remote)
@@ -640,13 +641,13 @@ cmd_update()
 				# Run fetch only if $sha1 isn't present or it
 				# is not reachable from a ref.
 				is_tip_reachable "$sm_path" "$sha1" ||
-				fetch_in_submodule "$sm_path" ||
+				fetch_in_submodule "$sm_path" $depth ||
 				die "$(eval_gettext "Unable to fetch in submodule path '\$displaypath'")"
 
 				# Now we tried the usual fetch, but $sha1 may
 				# not be reachable from any of the refs
 				is_tip_reachable "$sm_path" "$sha1" ||
-				fetch_in_submodule "$sm_path" "$sha1" ||
+				fetch_in_submodule "$sm_path" $depth "$sha1" ||
 				die "$(eval_gettext "Fetched in submodule path '\$displaypath', but it did not contain \$sha1. Direct fetching of that commit failed.")"
 			fi
 

t/t7406-submodule-update.sh

@@ -856,6 +856,22 @@ test_expect_success 'submodule update clone shallow submodule' '
 	)
 '
 
+test_expect_success 'submodule update clone shallow submodule outside of depth' '
+	test_when_finished "rm -rf super3" &&
+	git clone cloned super3 &&
+	pwd=$(pwd) &&
+	(
+		cd super3 &&
+		sed -e "s#url = ../#url = file://$pwd/#" <.gitmodules >.gitmodules.tmp &&
+		mv -f .gitmodules.tmp .gitmodules &&
+		test_must_fail git submodule update --init --depth=1 2>actual &&
+		test_i18ngrep "Direct fetching of that commit failed." actual &&
+		git -C ../submodule config uploadpack.allowReachableSHA1InWant true &&
+		git submodule update --init --depth=1 >actual &&
+		test 1 = $(git -C submodule log --oneline | wc -l)
+	)
+'
+
 test_expect_success 'submodule update --recursive drops module name before recursing' '
 	(cd super2 &&
 	 (cd deeper/submodule/subsubmodule &&