sd-event: fix sd_event_source_get_priority() (#4712)

To properly store priority in passed in pointer and return 0 for success.
Also add a test for verifying that it works correctly.

2 files changed, 5 insertions, 1 deletions

diff --git a/src/libsystemd/sd-event/sd-event.c b/src/libsystemd/sd-event/sd-event.c
index 9857f8b1fc..f94959adac 100644
--- a/src/libsystemd/sd-event/sd-event.c
+++ b/src/libsystemd/sd-event/sd-event.c
@@ -1539,7 +1539,8 @@ _public_ int sd_event_source_get_priority(sd_event_source *s, int64_t *priority)
         assert_return(s, -EINVAL);
         assert_return(!event_pid_changed(s->event), -ECHILD);
 
-        return s->priority;
+        *priority = s->priority;
+        return 0;
 }
 
 _public_ int sd_event_source_set_priority(sd_event_source *s, int64_t priority) {
diff --git a/src/libsystemd/sd-event/test-event.c b/src/libsystemd/sd-event/test-event.c
index 289114490c..c0e5e06a18 100644
--- a/src/libsystemd/sd-event/test-event.c
+++ b/src/libsystemd/sd-event/test-event.c
@@ -172,6 +172,7 @@ static void test_basic(void) {
         static const char ch = 'x';
         int a[2] = { -1, -1 }, b[2] = { -1, -1}, d[2] = { -1, -1}, k[2] = { -1, -1 };
         uint64_t event_now;
+        int64_t priority;
 
         assert_se(pipe(a) >= 0);
         assert_se(pipe(b) >= 0);
@@ -209,6 +210,8 @@ static void test_basic(void) {
         assert_se(sd_event_add_exit(e, &q, exit_handler, INT_TO_PTR('g')) >= 0);
 
         assert_se(sd_event_source_set_priority(x, 99) >= 0);
+        assert_se(sd_event_source_get_priority(x, &priority) >= 0);
+        assert_se(priority == 99);
         assert_se(sd_event_source_set_enabled(y, SD_EVENT_ONESHOT) >= 0);
         assert_se(sd_event_source_set_prepare(x, prepare_handler) >= 0);
         assert_se(sd_event_source_set_priority(z, 50) >= 0);