[CLOUD-1300] add nil check before accessing inside items (#1)

* add nil check before accessing inside items

* address PR comment

* update codeowners

Author: vishwajeetk1160

CODEOWNERS

@@ -1,2 +1,2 @@
-*                 @hashicorp/terraform-aws
-/.github/         @breathingdust @justinretzolk @hashicorp/terraform-aws
+# Global owners (fallback for unmatched files)
+* @sks @nasir-rabbani @Rchanger @vishwajeetk1160

internal/service/cloudfront/distribution.go

@@ -1496,15 +1496,15 @@ func flattenCacheBehavior(apiObject *awstypes.CacheBehavior) map[string]interfac
 		tfMap["forwarded_values"] = []interface{}{flattenForwardedValues(apiObject.ForwardedValues)}
 	}
 
-	if len(apiObject.FunctionAssociations.Items) > 0 {
+	if apiObject.FunctionAssociations != nil && len(apiObject.FunctionAssociations.Items) > 0 {
 		tfMap["function_association"] = flattenFunctionAssociations(apiObject.FunctionAssociations)
 	}
 
 	if apiObject.GrpcConfig != nil {
 		tfMap["grpc_config"] = []interface{}{flattenGRPCConfig(apiObject.GrpcConfig)}
 	}
 
-	if len(apiObject.LambdaFunctionAssociations.Items) > 0 {
+	if apiObject.LambdaFunctionAssociations != nil && len(apiObject.LambdaFunctionAssociations.Items) > 0 {
 		tfMap["lambda_function_association"] = flattenLambdaFunctionAssociations(apiObject.LambdaFunctionAssociations)
 	}
 
@@ -1520,11 +1520,11 @@ func flattenCacheBehavior(apiObject *awstypes.CacheBehavior) map[string]interfac
 		tfMap["smooth_streaming"] = aws.ToBool(apiObject.SmoothStreaming)
 	}
 
-	if len(apiObject.TrustedKeyGroups.Items) > 0 {
+	if apiObject.TrustedKeyGroups != nil && len(apiObject.TrustedKeyGroups.Items) > 0 {
 		tfMap["trusted_key_groups"] = flattenTrustedKeyGroups(apiObject.TrustedKeyGroups)
 	}
 
-	if len(apiObject.TrustedSigners.Items) > 0 {
+	if apiObject.TrustedSigners != nil && len(apiObject.TrustedSigners.Items) > 0 {
 		tfMap["trusted_signers"] = flattenTrustedSigners(apiObject.TrustedSigners)
 	}
 
@@ -1646,15 +1646,15 @@ func flattenDefaultCacheBehavior(apiObject *awstypes.DefaultCacheBehavior) map[s
 		tfMap["forwarded_values"] = []interface{}{flattenForwardedValues(apiObject.ForwardedValues)}
 	}
 
-	if len(apiObject.FunctionAssociations.Items) > 0 {
+	if apiObject.FunctionAssociations != nil && len(apiObject.FunctionAssociations.Items) > 0 {
 		tfMap["function_association"] = flattenFunctionAssociations(apiObject.FunctionAssociations)
 	}
 
 	if apiObject.GrpcConfig != nil {
 		tfMap["grpc_config"] = []interface{}{flattenGRPCConfig(apiObject.GrpcConfig)}
 	}
 
-	if len(apiObject.LambdaFunctionAssociations.Items) > 0 {
+	if apiObject.LambdaFunctionAssociations != nil && len(apiObject.LambdaFunctionAssociations.Items) > 0 {
 		tfMap["lambda_function_association"] = flattenLambdaFunctionAssociations(apiObject.LambdaFunctionAssociations)
 	}
 
@@ -1666,11 +1666,11 @@ func flattenDefaultCacheBehavior(apiObject *awstypes.DefaultCacheBehavior) map[s
 		tfMap["smooth_streaming"] = aws.ToBool(apiObject.SmoothStreaming)
 	}
 
-	if len(apiObject.TrustedKeyGroups.Items) > 0 {
+	if apiObject.TrustedKeyGroups != nil && len(apiObject.TrustedKeyGroups.Items) > 0 {
 		tfMap["trusted_key_groups"] = flattenTrustedKeyGroups(apiObject.TrustedKeyGroups)
 	}
 
-	if len(apiObject.TrustedSigners.Items) > 0 {
+	if apiObject.TrustedSigners != nil && len(apiObject.TrustedSigners.Items) > 0 {
 		tfMap["trusted_signers"] = flattenTrustedSigners(apiObject.TrustedSigners)
 	}