Don't return parent image for variations.

api/class-wc-rest-dev-product-variations-controller.php

@@ -76,7 +76,7 @@ public function prepare_object_for_response( $object, $request ) {
 			),
 			'shipping_class'        => $object->get_shipping_class(),
 			'shipping_class_id'     => $object->get_shipping_class_id(),
-			'image'                 => current( $this->get_images( $object ) ),
+			'image'                 => $this->get_image( $object ),
 			'attributes'            => $this->get_attributes( $object ),
 			'menu_order'            => $object->get_menu_order(),
 			'meta_data'             => $object->get_meta_data(),
@@ -307,20 +307,24 @@ protected function prepare_object_for_database( $request, $creating = false ) {
 	 * @param WC_Product_Variation $variation Variation
 	 * @return array
 	 */
-	protected function get_images( $variation ) {
+	protected function get_image( $variation ) {
+		if ( ! has_post_thumbnail( $variation->get_id() ) ) {
+			return;
+		}
+
 		$attachment_id = $variation->get_image_id();
 		$attachment_post = get_post( $attachment_id );
 		if ( is_null( $attachment_post ) ) {
-			$image = array();
+			return;
 		}
 
 		$attachment = wp_get_attachment_image_src( $attachment_id, 'full' );
 		if ( ! is_array( $attachment ) ) {
-			$image = array();
+			return;
 		}
 
 		if ( ! isset ( $image ) ) {
-			$image = array(
+			return array(
 				'id'                => (int) $attachment_id,
 				'date_created'      => wc_rest_prepare_date_response( $attachment_post->post_date, false ),
 				'date_created_gmt'  => wc_rest_prepare_date_response( strtotime( $attachment_post->post_date_gmt ) ),
@@ -332,7 +336,7 @@ protected function get_images( $variation ) {
 			);
 		}
 
-		return array( $image );
+		return;
 	}
 
 	/**