- Fixes an issue that can result in namespaced custom resources being orphaned when their namespace is deleted, if the CRD defining the custom resource is removed concurrently with namespaces being deleted, then recreated. ([#93790](https://github.com/kubernetes/kubernetes/pull/93790), [@liggitt](https://github.com/liggitt)) [SIG API Machinery and Apps]

* Addon manager supports HA masters. ([#55782](https://github.com/kubernetes/kubernetes/pull/55782), [@x13n](https://github.com/x13n))

- Restore the ability to `kubectl apply --prune` without --namespace flag.  Since 1.17, `kubectl apply --prune` only prunes resources in the default namespace (or from kubeconfig) or explicitly specified in command line flag.  But this is s breaking change from kubectl 1.16, which can prune resources in all namespace in config file.  This patch restores the kubectl 1.16 behaviour. ([#89551](https://github.com/kubernetes/kubernetes/pull/89551),...

### Bug or Regression

- Fixes a spurious "namespace not found" error possible in default configurations in 1.30+ when using ValidatingAdmissionPolicy or MutatingAdmissionPolicy to intercept namespaced objects in newly-created namespaces ([#135442](https://github.com/kubernetes/kubernetes/pull/135442), [@lalitc375](https://github.com/lalitc375)) [SIG API Machinery]

- Existing InTree AzureFile PVs which don't have a secret namespace defined will now work properly after enabling CSI migration - the namespace will be obtained from ClaimRef. ([#108000](https://github.com/kubernetes/kubernetes/pull/108000), [@RomanBednar](https://github.com/RomanBednar)) [SIG Cloud Provider and Storage]

	return &nsMutex
}

// nsLock - provides primitives for locking critical namespace regions.
type nsLock struct {
	ref int32
	*lsync.LRWMutex
}

// nsLockMap - namespace lock map, provides primitives to Lock,
// Unlock, RLock and RUnlock.
type nsLockMap struct {
	// Indicates if namespace is part of a distributed setup.
	isDistErasure bool
	lockMap       map[string]*nsLock
	lockMapMutex  sync.Mutex

// Tests getSource().
func TestGetSource(t *testing.T) {
	currentSource := func() string { return getSource(2) }
	gotSource := currentSource()
	// Hard coded line number, 34, in the "expectedSource" value
	expectedSource := "[namespace-lock_test.go:34:TestGetSource()]"
	if gotSource != expectedSource {
		t.Errorf("expected : %s, got : %s", expectedSource, gotSource)
	}
}

// Test lock race
func TestNSLockRace(t *testing.T) {

- Return a warning when applying a `pod-security.kubernetes.io` label to a PodSecurity-exempted namespace.
  Stop including the `pod-security.kubernetes.io/exempt=namespace` audit annotation on namespace requests. ([#109680](https://github.com/kubernetes/kubernetes/pull/109680), [@tallclair](https://github.com/tallclair))

- Kube-apiserver: ensures the namespace of objects sent to admission webhooks matches the request namespace. Previously, objects without a namespace set would have the request namespace populated after mutating admission, and objects with a namespace that did not match the request namespace would be rejected after admission. ([#94637](https://github.com/kubernetes/kubernetes/pull/94637), [@liggitt](https://github.com/liggitt))...

import static eu.maveniverse.domtrip.maven.MavenPomElements.Namespaces.MAVEN_4_0_0_NAMESPACE;
import static eu.maveniverse.domtrip.maven.MavenPomElements.Namespaces.MAVEN_4_1_0_NAMESPACE;
import static org.apache.maven.cling.invoker.mvnup.goals.ModelVersionUtils.getSchemaLocationForModelVersion;

/**
 * Strategy for upgrading Maven model versions (e.g., 4.0.0 → 4.1.0).
 * Handles namespace updates, schema location changes, and element conversions.
 */