Merge pull request #122152 from pohly/client-go-event-context-fix

client-go events: support context.Background() as context

staging/src/k8s.io/client-go/tools/record/event.go

@@ -198,16 +198,29 @@ func NewBroadcaster(opts ...BroadcasterOption) EventBroadcaster {
 	ctx := c.Context
 	if ctx == nil {
 		ctx = context.Background()
-	} else {
+	}
+	// The are two scenarios where it makes no sense to wait for context cancelation:
+	// - The context was nil.
+	// - The context was context.Background() to begin with.
+	//
+	// Both cases get checked here.
+	haveCtxCancelation := ctx.Done() == nil
+
+	eventBroadcaster.cancelationCtx, eventBroadcaster.cancel = context.WithCancel(ctx)
+
+	if haveCtxCancelation {
 		// Calling Shutdown is not required when a context was provided:
 		// when the context is canceled, this goroutine will shut down
 		// the broadcaster.
+		//
+		// If Shutdown is called first, then this goroutine will
+		// also stop.
 		go func() {
-			<-ctx.Done()
+			<-eventBroadcaster.cancelationCtx.Done()
 			eventBroadcaster.Broadcaster.Shutdown()
 		}()
 	}
-	eventBroadcaster.cancelationCtx, eventBroadcaster.cancel = context.WithCancel(ctx)
+
 	return eventBroadcaster
 }