submodule: use prepare_submodule_repo_env consistently

Before 14111fc (git: submodule honor -c credential.* from
command line, 2016-02-29), it was sufficient for code which
spawned a process in a submodule to just set the child
process's "env" field to "local_repo_env" to clear the
environment of any repo-specific variables.

That commit introduced a more complicated procedure, in
which we clear most variables but allow through sanitized
config. For C code, we used that procedure only for cloning,
but not for any of the programs spawned by submodule.c. As a
result, things like "git fetch --recurse-submodules" behave
differently than "git clone --recursive"; the former will
not pass through the sanitized config.

We can fix this by using prepare_submodule_repo_env()
everywhere in submodule.c.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 11 insertions, 0 deletions

diff --git a/t/t5550-http-fetch-dumb.sh b/t/t5550-http-fetch-dumb.sh
index 13ac788fde..3484b6f0f3 100755
--- a/t/t5550-http-fetch-dumb.sh
+++ b/t/t5550-http-fetch-dumb.sh
@@ -112,6 +112,17 @@ test_expect_success 'cmdline credential config passes to submodule via clone' '
 	expect_askpass pass user@host
 '
 
+test_expect_success 'cmdline credential config passes submodule via fetch' '
+	set_askpass wrong pass@host &&
+	test_must_fail git -C super-clone fetch --recurse-submodules &&
+
+	set_askpass wrong pass@host &&
+	git -C super-clone \
+	    -c "credential.$HTTPD_URL.username=user@host" \
+	    fetch --recurse-submodules &&
+	expect_askpass pass user@host
+'
+
 test_expect_success 'cmdline credential config passes submodule update' '
 	# advance the submodule HEAD so that a fetch is required
 	git commit --allow-empty -m foo &&