fix: guard against undefined properties on license object in Library (#1269)

* fix: guard against undefined properties on license object in Library

When the license option is stored as a stdClass without `key` or
`download_id` properties (e.g. on a free/unlicensed install), PHP 8
throws an undefined-property notice.  Add isset() guards so both
properties fall back to an empty string.

* fix: fix telemetry error

Author: HardeepAsrani

classes/Visualizer/Render/Library.php

@@ -223,8 +223,8 @@ private function _renderProPopupBlocker() {
 		$license_key = '';
 		$download_id = '';
 		if ( ! empty( $license ) && is_object( $license ) ) {
-			$license_key = $license->key;
-			$download_id = $license->download_id;
+			$license_key = isset( $license->key ) ? $license->key : '';
+			$download_id = isset( $license->download_id ) ? $license->download_id : '';
 		}
 		$admin_license_url = admin_url( 'options-general.php#visualizer_pro_license' );
 		$renew_license_url = tsdk_utmify( Visualizer_Plugin::STORE_URL . '?edd_license_key=' . $license_key . '&download_id=' . $download_id, 'visualizer_license_block' );

index.php

@@ -169,7 +169,7 @@ function ( $products ) {
 
 				$license = get_option( 'visualizer_pro_license_data', 'free' );
 				if ( ! empty( $license ) && is_object( $license ) ) {
-					$license = $license->key;
+					$license = $license->key ?? 'free';
 				}
 				$track_hash = 'free' === $license ? 'free' : wp_hash( $license );