1 files changed, 13 insertions, 0 deletions
diff --git a/internal/lock/lock_test.go b/internal/lock/lock_test.go
index fca4d76..53ce5ca 100644
--- a/internal/lock/lock_test.go
+++ b/internal/lock/lock_test.go
@@ -122,3 +122,16 @@ func TestStaleLockIsTakenOver(t *testing.T) {
 		t.Error("the takeover was not reported to the caller")
 	}
 }
+
+// TestRunningRejectsPidsBeyondTheKernelsRange: a pid wider than 32 bits in a
+// damaged lock file is cut to its low bits by kill(2), so without a range
+// check it names some other process - here this very one - and a stale lock
+// would never be taken over.
+func TestRunningRejectsPidsBeyondTheKernelsRange(t *testing.T) {
+	if running(os.Getpid() + 1<<32) {
+		t.Error("running(pid + 2^32) is true: the pid was truncated to this process")
+	}
+	if !running(os.Getpid()) {
+		t.Error("running(own pid) is false")
+	}
+}