Allocate map when out points to nil map

Kubernetes-commit: 53080bda9c95db33227b02b5b7df7e7737a2904e

Author: yutedz

tools/clientcmd/api/v1/conversion.go

@@ -31,6 +31,9 @@ func Convert_Slice_v1_NamedCluster_To_Map_string_To_Pointer_api_Cluster(in *[]Na
 		if err := Convert_v1_Cluster_To_api_Cluster(&curr.Cluster, newCluster, s); err != nil {
 			return err
 		}
+		if *out == nil {
+			*out = make(map[string]*api.Cluster)
+		}
 		if (*out)[curr.Name] == nil {
 			(*out)[curr.Name] = newCluster
 		} else {
@@ -65,6 +68,9 @@ func Convert_Slice_v1_NamedAuthInfo_To_Map_string_To_Pointer_api_AuthInfo(in *[]
 		if err := Convert_v1_AuthInfo_To_api_AuthInfo(&curr.AuthInfo, newAuthInfo, s); err != nil {
 			return err
 		}
+		if *out == nil {
+			*out = make(map[string]*api.AuthInfo)
+		}
 		if (*out)[curr.Name] == nil {
 			(*out)[curr.Name] = newAuthInfo
 		} else {
@@ -99,6 +105,9 @@ func Convert_Slice_v1_NamedContext_To_Map_string_To_Pointer_api_Context(in *[]Na
 		if err := Convert_v1_Context_To_api_Context(&curr.Context, newContext, s); err != nil {
 			return err
 		}
+		if *out == nil {
+			*out = make(map[string]*api.Context)
+		}
 		if (*out)[curr.Name] == nil {
 			(*out)[curr.Name] = newContext
 		} else {
@@ -133,6 +142,9 @@ func Convert_Slice_v1_NamedExtension_To_Map_string_To_runtime_Object(in *[]Named
 		if err := runtime.Convert_runtime_RawExtension_To_runtime_Object(&curr.Extension, &newExtension, s); err != nil {
 			return err
 		}
+		if *out == nil {
+			*out = make(map[string]runtime.Object)
+		}
 		if (*out)[curr.Name] == nil {
 			(*out)[curr.Name] = newExtension
 		} else {

tools/clientcmd/loader_test.go

@@ -80,6 +80,32 @@ var (
 	}
 )
 
+func TestNilOutMap(t *testing.T) {
+	var fakeKubeconfigData = `apiVersion: v1
+kind: Config
+clusters:
+- cluster:
+    certificate-authority-data: UEhPTlkK
+    server: https://1.1.1.1
+  name: production
+contexts:
+- context:
+    cluster: production
+    user: production
+  name: production
+current-context: production
+users:
+- name: production
+  user:
+    auth-provider:
+      name: gcp`
+
+	_, _, err := clientcmdlatest.Codec.Decode([]byte(fakeKubeconfigData), nil, nil)
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+}
+
 func TestNonExistentCommandLineFile(t *testing.T) {
 	loadingRules := ClientConfigLoadingRules{
 		ExplicitPath: "bogus_file",