Merge branch 'sb/submodule-fetchjobs-default-to-one'

"git submodule update" ought to use a single job unless asked, but
by mistake used multiple jobs, which has been fixed.

* sb/submodule-fetchjobs-default-to-one:
  submodule update: run at most one fetch job unless otherwise set

builtin/submodule--helper.c

@@ -1552,7 +1552,7 @@ struct submodule_update_clone {
 #define SUBMODULE_UPDATE_CLONE_INIT {0, MODULE_LIST_INIT, 0, \
 	SUBMODULE_UPDATE_STRATEGY_INIT, 0, 0, -1, STRING_LIST_INIT_DUP, 0, \
 	NULL, NULL, NULL, \
-	NULL, 0, 0, 0, NULL, 0, 0, 0}
+	NULL, 0, 0, 0, NULL, 0, 0, 1}
 
 
 static void next_submodule_warn_missing(struct submodule_update_clone *suc,

t/t5526-fetch-submodules.sh

@@ -524,6 +524,8 @@ test_expect_success 'fetching submodules respects parallel settings' '
 	git config fetch.recurseSubmodules true &&
 	(
 		cd downstream &&
+		GIT_TRACE=$(pwd)/trace.out git fetch &&
+		grep "1 tasks" trace.out &&
 		GIT_TRACE=$(pwd)/trace.out git fetch --jobs 7 &&
 		grep "7 tasks" trace.out &&
 		git config submodule.fetchJobs 8 &&