[libgpiod] [PATCH 13/19] core: allow gpiod_line_set_value_bulk to accept null values

[Kent Gibson <warthog618@gmail.com>]

Change gpiod_line_set_value_bulk to interpret a NULL values pointer as an
array of zero, as per gpiod_line_request_bulk, gpiod_line_set_config_bulk,
and gpiod_line_set_direction_bulk_output.

The old behaviour was to segfault.

Signed-off-by: Kent Gibson <warthog618@gmail.com>
---
 lib/core.c         |  5 +++--
 tests/tests-line.c | 53 ++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 56 insertions(+), 2 deletions(-)

diff --git a/lib/core.c b/lib/core.c
index c42cda5..2e54def 100644
--- a/lib/core.c
+++ b/lib/core.c
@@ -805,8 +805,9 @@ int gpiod_line_set_value_bulk(struct gpiod_line_bulk *bulk, const int *values)
 
 	memset(&data, 0, sizeof(data));
 
-	for (i = 0; i < gpiod_line_bulk_num_lines(bulk); i++)
-		data.values[i] = (uint8_t)!!values[i];
+	if (values)
+		for (i = 0; i < gpiod_line_bulk_num_lines(bulk); i++)
+			data.values[i] = (uint8_t)!!values[i];
 
 	line = gpiod_line_bulk_get_line(bulk, 0);
 	fd = line_get_fd(line);
diff --git a/tests/tests-line.c b/tests/tests-line.c
index e74f90f..7d45603 100644
--- a/tests/tests-line.c
+++ b/tests/tests-line.c
@@ -277,6 +277,59 @@ GPIOD_TEST_CASE(set_value, 0, { 8 })
 	g_assert_cmpint(gpiod_test_chip_get_value(0, 2), ==, 0);
 }
 
+GPIOD_TEST_CASE(set_value_bulk, 0, { 8 })
+{
+	g_autoptr(gpiod_chip_struct) chip = NULL;
+	struct gpiod_line_bulk bulk = GPIOD_LINE_BULK_INITIALIZER;
+	struct gpiod_line *line0, *line1, *line2;
+	int values[3];
+	gint ret;
+
+	chip = gpiod_chip_open(gpiod_test_chip_path(0));
+	g_assert_nonnull(chip);
+	gpiod_test_return_if_failed();
+
+	line0 = gpiod_chip_get_line(chip, 0);
+	line1 = gpiod_chip_get_line(chip, 1);
+	line2 = gpiod_chip_get_line(chip, 2);
+
+	g_assert_nonnull(line0);
+	g_assert_nonnull(line1);
+	g_assert_nonnull(line2);
+	gpiod_test_return_if_failed();
+
+	gpiod_line_bulk_add(&bulk, line0);
+	gpiod_line_bulk_add(&bulk, line1);
+	gpiod_line_bulk_add(&bulk, line2);
+
+	values[0] = 0;
+	values[1] = 1;
+	values[2] = 2;
+
+	ret = gpiod_line_request_bulk_output(&bulk,
+			GPIOD_TEST_CONSUMER, values);
+	g_assert_cmpint(ret, ==, 0);
+	g_assert_cmpint(gpiod_test_chip_get_value(0, 0), ==, 0);
+	g_assert_cmpint(gpiod_test_chip_get_value(0, 1), ==, 1);
+	g_assert_cmpint(gpiod_test_chip_get_value(0, 2), ==, 1);
+
+	values[0] = 2;
+	values[1] = 1;
+	values[2] = 0;
+
+	ret = gpiod_line_set_value_bulk(&bulk, values);
+	g_assert_cmpint(ret, ==, 0);
+	g_assert_cmpint(gpiod_test_chip_get_value(0, 0), ==, 1);
+	g_assert_cmpint(gpiod_test_chip_get_value(0, 1), ==, 1);
+	g_assert_cmpint(gpiod_test_chip_get_value(0, 2), ==, 0);
+
+	ret = gpiod_line_set_value_bulk(&bulk, NULL);
+	g_assert_cmpint(ret, ==, 0);
+	g_assert_cmpint(gpiod_test_chip_get_value(0, 0), ==, 0);
+	g_assert_cmpint(gpiod_test_chip_get_value(0, 1), ==, 0);
+	g_assert_cmpint(gpiod_test_chip_get_value(0, 2), ==, 0);
+}
+
 GPIOD_TEST_CASE(set_config_bulk_null_values, 0, { 8 })
 {
 	g_autoptr(gpiod_chip_struct) chip = NULL;
-- 
2.24.0