tests: ignore 'remove' events from udev

So far the tests have been executed on a Debian 9 machine with libudev
provided by systemd 232 - everything always worked fine. However
running them on a system with systemd 237 uncovered a bug in the
testing framework.

It turned out that on newer versions the ignored 'remove' events linger
somewhere in the pipeline and get read by subsequent test cases causing
erroneous chip naming and breaking tests.

Check the action string for udev device objects and only care about
those being added.

Signed-off-by: Bartosz Golaszewski <bartekgola@gmail.com>

diff --git a/tests/gpiod-test.c b/tests/gpiod-test.c
index 92d6b7875fefcb4e02b0f54616f513d2d252a17c..01773016921a1e8c8c77437358ec9597b69af4e8 100644 (file)
--- a/tests/gpiod-test.c
+++ b/tests/gpiod-test.c
@@ -810,7 +810,7 @@ static bool devpath_is_mockup(const char *devpath)
 
 static void prepare_test(struct _test_chip_descr *descr)
 {
-       const char *devpath, *devnode, *sysname;
+       const char *devpath, *devnode, *sysname, *action;
        struct udev_monitor *monitor;
        unsigned int detected = 0;
        struct test_context *ctx;
@@ -868,9 +868,11 @@ static void prepare_test(struct _test_chip_descr *descr)
                devpath = udev_device_get_devpath(dev);
                devnode = udev_device_get_devnode(dev);
                sysname = udev_device_get_sysname(dev);
+               action = udev_device_get_action(dev);
 
                if (!devpath || !devnode || !sysname ||
-                   !devpath_is_mockup(devpath)) {
+                   !devpath_is_mockup(devpath) ||
+                   strcmp(action, "add") != 0) {
                        udev_device_unref(dev);
                        continue;
                }