Initialize default attach func regardless of the value of flag

Kubernetes-commit: cde050c4d0b02003d34f7056bd038fe8f4accc42

pkg/cmd/debug/debug.go

@@ -213,14 +213,15 @@ func (o *DebugOptions) Complete(restClientGetter genericclioptions.RESTClientGet
 	attachFlag := cmd.Flags().Lookup("attach")
 	if !attachFlag.Changed && o.Interactive {
 		o.Attach = true
-		// Downstream tools may want to use their own customized
-		// attach function to do extra work or use attach command
-		// with different flags instead of the static one defined in
-		// handleAttachPod. But if this function is not set explicitly,
-		// we fall back to default.
-		if o.AttachFunc == nil {
-			o.AttachFunc = o.handleAttachPod
-		}
+	}
+
+	// Downstream tools may want to use their own customized
+	// attach function to do extra work or use attach command
+	// with different flags instead of the static one defined in
+	// handleAttachPod. But if this function is not set explicitly,
+	// we fall back to default.
+	if o.AttachFunc == nil {
+		o.AttachFunc = o.handleAttachPod
 	}
 
 	// Environment