tests: add a test case for incorrect retrieving of edge events from buffer

Add a test case that makes sure we don't crash when trying to access an
out-of-bounds edge event in an edge event buffer.

Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

1 files changed, 42 insertions, 0 deletions

diff --git a/tests/tests-edge-event.c b/tests/tests-edge-event.c
index 0ff7dc88..e79f4579 100644
--- a/tests/tests-edge-event.c
+++ b/tests/tests-edge-event.c
@@ -639,3 +639,45 @@ GPIOD_TEST_CASE(null_buffer)
 	g_assert_cmpint(ret, ==, -1);
 	gpiod_test_expect_errno(EINVAL);
 }
+
+GPIOD_TEST_CASE(get_edge_event_index_out_of_bounds)
+{
+	static const guint offset = 2;
+
+	g_autoptr(GPIOSimChip) sim = g_gpiosim_chip_new("num-lines", 8, NULL);
+	g_autoptr(struct_gpiod_chip) chip = NULL;
+	g_autoptr(struct_gpiod_line_settings) settings = NULL;
+	g_autoptr(struct_gpiod_line_config) line_cfg = NULL;
+	g_autoptr(struct_gpiod_line_request) request = NULL;
+	g_autoptr(struct_gpiod_edge_event_buffer) buffer = NULL;
+	struct gpiod_edge_event *event;
+	gint ret;
+
+	chip = gpiod_test_open_chip_or_fail(g_gpiosim_chip_get_dev_path(sim));
+	settings = gpiod_test_create_line_settings_or_fail();
+	line_cfg = gpiod_test_create_line_config_or_fail();
+	buffer = gpiod_test_create_edge_event_buffer_or_fail(64);
+
+	gpiod_line_settings_set_direction(settings, GPIOD_LINE_DIRECTION_INPUT);
+	gpiod_line_settings_set_edge_detection(settings, GPIOD_LINE_EDGE_BOTH);
+
+	gpiod_test_line_config_add_line_settings_or_fail(line_cfg, &offset, 1,
+							 settings);
+
+	request = gpiod_test_request_lines_or_fail(chip, NULL, line_cfg);
+
+	g_gpiosim_chip_set_pull(sim, 2, G_GPIOSIM_PULL_UP);
+	g_usleep(500);
+	g_gpiosim_chip_set_pull(sim, 2, G_GPIOSIM_PULL_DOWN);
+	g_usleep(500);
+	g_gpiosim_chip_set_pull(sim, 2, G_GPIOSIM_PULL_UP);
+	g_usleep(500);
+
+	ret = gpiod_line_request_read_edge_events(request, buffer, 3);
+	g_assert_cmpint(ret, ==, 3);
+	gpiod_test_return_if_failed();
+
+	event = gpiod_edge_event_buffer_get_event(buffer, 5);
+	g_assert_null(event);
+	gpiod_test_expect_errno(EINVAL);
+}