fetch: pass --no-write-fetch-head to subprocesses

It seems a user would expect this option would work regardless
of whether it's fetching from a single remote, many remotes,
or recursing into submodules.

Signed-off-by: Eric Wong <e@80x24.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

builtin/fetch.c

@@ -1880,6 +1880,8 @@ static void add_options_to_argv(struct strvec *argv)
 		strvec_push(argv, "--ipv4");
 	else if (family == TRANSPORT_FAMILY_IPV6)
 		strvec_push(argv, "--ipv6");
+	if (!write_fetch_head)
+		strvec_push(argv, "--no-write-fetch-head");
 }
 
 /* Fetch multiple remotes in parallel */

t/t5514-fetch-multiple.sh

@@ -58,6 +58,13 @@ test_expect_success 'git fetch --all' '
 	 test_cmp expect output)
 '
 
+test_expect_success 'git fetch --all --no-write-fetch-head' '
+	(cd test &&
+	rm -f .git/FETCH_HEAD &&
+	git fetch --all --no-write-fetch-head &&
+	test_path_is_missing .git/FETCH_HEAD)
+'
+
 test_expect_success 'git fetch --all should continue if a remote has errors' '
 	(git clone one test2 &&
 	 cd test2 &&

t/t5526-fetch-submodules.sh

@@ -167,6 +167,19 @@ test_expect_success "fetch --recurse-submodules recurses into submodules" '
 	verify_fetch_result actual.err
 '
 
+test_expect_success "fetch --recurse-submodules honors --no-write-fetch-head" '
+	(
+		cd downstream &&
+		git submodule foreach --recursive \
+		sh -c "cd \"\$(git rev-parse --git-dir)\" && rm -f FETCH_HEAD" &&
+
+		git fetch --recurse-submodules --no-write-fetch-head &&
+
+		git submodule foreach --recursive \
+		sh -c "cd \"\$(git rev-parse --git-dir)\" && ! test -f FETCH_HEAD"
+	)
+'
+
 test_expect_success "submodule.recurse option triggers recursive fetch" '
 	add_submodule_commits &&
 	(