### Bug or Regression

- Client-go: resolves an issue with informers falling back to full list requests when timeouts are encountered, rather than re-establishing a watch. ([#89977](https://github.com/kubernetes/kubernetes/pull/89977), [@liggitt](https://github.com/liggitt)) [SIG API Machinery and Testing]

- Fix memory leak in kube-apiserver when underlying time goes forth and back. ([#96266](https://github.com/kubernetes/kubernetes/pull/96266), [@chenyw1990](https://github.com/chenyw1990)) [SIG API Machinery]

- Parsing of cpuset information now properly detects more invalid input such as `1--3` or `10-6`. ([#100565](https://github.com/kubernetes/kubernetes/pull/100565), [@lack](https://github.com/lack))

   ([#123261](https://github.com/kubernetes/kubernetes/pull/123261), [@skitt](https://github.com/skitt))
- Reverted the `EventedPLEG` feature (beta, but disabled by default) back to alpha due to a known issue.
   ([#122697](https://github.com/kubernetes/kubernetes/pull/122697), [@pacoxu](https://github.com/pacoxu))
- Used `errors.Is()` to handle errors returned by `LookPath()`.

## Changelog since v1.15.11

## Changes by Kind

### Bug or Regression

- Client-go: resolves an issue with informers falling back to full list requests when timeouts are encountered, rather than re-establishing a watch. ([#89978](https://github.com/kubernetes/kubernetes/pull/89978), [@liggitt](https://github.com/liggitt)) [SIG API Machinery and Testing]

raw string literals and interpreted string literals.
</p>

<p>
Raw string literals are character sequences between back quotes, as in
<code>`foo`</code>.  Within the quotes, any character may appear except
back quote. The value of a raw string literal is the
string composed of the uninterpreted (implicitly UTF-8-encoded) characters
between the quotes;

				dsc.Set(newReplicateTargetDecision(tgtArn, replicate, sync))
				continue
			}
			// can be the case that other cluster is down and duplicate `mc rm --vid`
			// is issued - this still needs to be replicated back to the other target
			if !oi.VersionPurgeStatus.Empty() {
				replicate = oi.VersionPurgeStatus == replication.VersionPurgePending || oi.VersionPurgeStatus == replication.VersionPurgeFailed

    client =
      client
        .newBuilder()
        .hostnameVerifier(
          RecordingHostnameVerifier(),
        ) // Attempt RESTRICTED_TLS then fall back to MODERN_TLS.
        .connectionSpecs(Arrays.asList(ConnectionSpec.RESTRICTED_TLS, ConnectionSpec.MODERN_TLS))
        .sslSocketFactory(
          suppressTlsFallbackClientSocketFactory(),

* Fixed scanning of failed iSCSI targets. ([#74306](https://github.com/kubernetes/kubernetes/pull/74306), [@jsafrane](https://github.com/jsafrane))
* fix detach azure disk back off issue which has too big lock in failure retry condition ([#76573](https://github.com/kubernetes/kubernetes/pull/76573), [@andyzhangx](https://github.com/andyzhangx))

		// Note that url.Parse does the unescaping
		cpSrcPath = u.Path
	}

	srcBucket, srcObject := path2BucketObject(cpSrcPath)
	// If source object is empty or bucket is empty, reply back invalid copy source.
	if srcObject == "" || srcBucket == "" {
		writeErrorResponse(ctx, w, errorCodes.ToAPIErr(ErrInvalidCopySource), r.URL)
		return
	}