Narrow merge interface to merging the same types

Author: liggitt

staging/src/k8s.io/client-go/tools/clientcmd/client_config.go

@@ -508,7 +508,7 @@ func (config *DirectClientConfig) getContext() (clientcmdapi.Context, error) {
 		return clientcmdapi.Context{}, fmt.Errorf("context %q does not exist", contextName)
 	}
 	if config.overrides != nil {
-		if err := merge(mergedContext, config.overrides.Context); err != nil {
+		if err := merge(mergedContext, &config.overrides.Context); err != nil {
 			return clientcmdapi.Context{}, err
 		}
 	}
@@ -530,7 +530,7 @@ func (config *DirectClientConfig) getAuthInfo() (clientcmdapi.AuthInfo, error) {
 		return clientcmdapi.AuthInfo{}, fmt.Errorf("auth info %q does not exist", authInfoName)
 	}
 	if config.overrides != nil {
-		if err := merge(mergedAuthInfo, config.overrides.AuthInfo); err != nil {
+		if err := merge(mergedAuthInfo, &config.overrides.AuthInfo); err != nil {
 			return clientcmdapi.AuthInfo{}, err
 		}
 	}
@@ -545,7 +545,7 @@ func (config *DirectClientConfig) getCluster() (clientcmdapi.Cluster, error) {
 
 	mergedClusterInfo := clientcmdapi.NewCluster()
 	if config.overrides != nil {
-		if err := merge(mergedClusterInfo, config.overrides.ClusterDefaults); err != nil {
+		if err := merge(mergedClusterInfo, &config.overrides.ClusterDefaults); err != nil {
 			return clientcmdapi.Cluster{}, err
 		}
 	}
@@ -557,7 +557,7 @@ func (config *DirectClientConfig) getCluster() (clientcmdapi.Cluster, error) {
 		return clientcmdapi.Cluster{}, fmt.Errorf("cluster %q does not exist", clusterInfoName)
 	}
 	if config.overrides != nil {
-		if err := merge(mergedClusterInfo, config.overrides.ClusterInfo); err != nil {
+		if err := merge(mergedClusterInfo, &config.overrides.ClusterInfo); err != nil {
 			return clientcmdapi.Cluster{}, err
 		}
 	}

staging/src/k8s.io/client-go/tools/clientcmd/merge.go

@@ -24,6 +24,6 @@ import (
 // - non-pointer struct fields are recursively merged
 // - maps are shallow merged with src keys taking priority over dst
 // - non-zero src fields encountered during recursion that are not maps or structs overwrite and recursion stops
-func merge(dst, src any) error {
+func merge[T any](dst, src *T) error {
 	return mergo.Merge(dst, src, mergo.WithOverride)
 }