*  Fix: Drop cookies that contain ASCII NULL and other bad characters. Previously such cookies
    would cause OkHttp to crash when they were included in a request.
 *  Fix: Release duplicated multiplexed connections. If we concurrently establish connections to an
    HTTP/2 server, close all but the first connection.
 *  Fix: Fail the HTTP/2 connection if first frame isn't `SETTINGS`.

- Fixed a bug that caused duplicate validation when updating a ReplicaSet. ([#131873](https://github.com/kubernetes/kubernetes/pull/131873), [@gavinkflam](https://github.com/gavinkflam)) [SIG Apps]

- Duplicate owner reference entries in create/update/patch requests now get deduplicated by the API server. The client sending the request now receives a warning header in the API response. Clients should stop sending requests with duplicate owner references. The API server may reject such requests as early as 1.24. ([#96185](https://github.com/kubernetes/kubernetes/pull/96185),...

- Kubeadm: fixed the bug that `kubeadm certs generate-csr` command does not remove duplicated SANs ([#107982](https://github.com/kubernetes/kubernetes/pull/107982), [@SataQiu](https://github.com/SataQiu))

* Made multi-scheduler graduated to Beta and then v1. ([#38871](https://github.com/kubernetes/kubernetes/pull/38871), [@k82cn](https://github.com/k82cn))
* Fixed forming resolver search line for pods: exclude duplicates, obey libc limitations, logging and eventing appropriately. ([#29666](https://github.com/kubernetes/kubernetes/pull/29666), [@vefimova](https://github.com/vefimova))

  - `spec.usages` is now required, may not contain duplicate values, and must only contain known usages
  - `status.conditions` may not contain duplicate types
  - `status.conditions[*].status` is now required

- KEP-1880: Users of the new feature to add multiple service CIDR will use by default a dual-write strategy on the new ClusterIP allocators to avoid the problem of possible duplicate IPs allocated to Services when running skewed kube-apiservers using different allocators. They can opt-out of this behavior by enabled the feature gate DisableAllocatorDualWrite. ([#122047](https://github.com/kubernetes/kubernetes/pull/122047), ...

    int getHash();

    /** Gets the key for this entry. */
    K getKey();

    /** Gets the value for the entry. */
    V getValue();
  }

  /*
   * Note: the following classes have a lot of duplicate code. It sucks, but it saves a lot of
   * memory. If only Java had mixins!
   */

  /** Base class for {@link InternalEntry} implementations for strong keys. */

- Fixed a bug which kubectl would emit duplicate warning messages for flag names that contain an underscore and recommend using a nonexistent flag in some cases. ([#103852](https://github.com/kubernetes/kubernetes/pull/103852), [@brianpursley](https://github.com/brianpursley))

- Fixed a regression in default configurations, which enabled PodDisruptionConditions by default, 
  that prevented the control plane's pod garbage collector from deleting pods that contained duplicated field keys (env. variables with repeated keys or container ports). ([#121379](https://github.com/kubernetes/kubernetes/pull/121379), [@mimowo](https://github.com/mimowo)) [SIG Apps, Auth, Node, Scheduling and Testing]