submodule tests: test for init and update failure output

Amend some submodule tests to test for the failure output of "git
submodule [update|init]". The lack of such tests hid a regression in
an earlier version of a subsequent commit.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Glen Choo <chooglen@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

t/t7406-submodule-update.sh

@@ -205,8 +205,18 @@ test_expect_success 'submodule update should fail due to local changes' '
 	 (cd submodule &&
 	  compare_head
 	 ) &&
-	 test_must_fail git submodule update submodule
-	)
+	 test_must_fail git submodule update submodule 2>../actual.raw
+	) &&
+	sed "s/^> //" >expect <<-\EOF &&
+	> error: Your local changes to the following files would be overwritten by checkout:
+	> 	file
+	> Please commit your changes or stash them before you switch branches.
+	> Aborting
+	> fatal: Unable to checkout OID in submodule path '\''submodule'\''
+	EOF
+	sed -e "s/checkout $SQ[^$SQ]*$SQ/checkout OID/" <actual.raw >actual &&
+	test_cmp expect actual
+
 '
 test_expect_success 'submodule update should throw away changes with --force ' '
 	(cd super &&

t/t7408-submodule-reference.sh

@@ -193,7 +193,19 @@ test_expect_success 'missing nested submodule alternate fails clone and submodul
 		cd supersuper-clone &&
 		check_that_two_of_three_alternates_are_used &&
 		# update of the submodule fails
-		test_must_fail git submodule update --init --recursive
+		cat >expect <<-\EOF &&
+		fatal: submodule '\''sub'\'' cannot add alternate: path ... does not exist
+		Failed to clone '\''sub'\''. Retry scheduled
+		fatal: submodule '\''sub-dissociate'\'' cannot add alternate: path ... does not exist
+		Failed to clone '\''sub-dissociate'\''. Retry scheduled
+		fatal: submodule '\''sub'\'' cannot add alternate: path ... does not exist
+		Failed to clone '\''sub'\'' a second time, aborting
+		fatal: Failed to recurse into submodule path ...
+		EOF
+		test_must_fail git submodule update --init --recursive 2>err &&
+		grep -e fatal: -e ^Failed err >actual.raw &&
+		sed -e "s/path $SQ[^$SQ]*$SQ/path .../" <actual.raw >actual &&
+		test_cmp expect actual
 	)
 '