Adding upstream version 0.28.1.

Signed-off-by: Daniel Baumann <daniel@debian.org>

tools/hook/event_test.go

@@ -0,0 +1,29 @@
+package hook
+
+import "testing"
+
+func TestEventNext(t *testing.T) {
+	calls := 0
+
+	e := Event{}
+
+	if e.nextFunc() != nil {
+		t.Fatalf("Expected nextFunc to be nil")
+	}
+
+	e.setNextFunc(func() error {
+		calls++
+		return nil
+	})
+
+	if e.nextFunc() == nil {
+		t.Fatalf("Expected nextFunc to be non-nil")
+	}
+
+	e.Next()
+	e.Next()
+
+	if calls != 2 {
+		t.Fatalf("Expected %d calls, got %d", 2, calls)
+	}
+}