From ff4ba58c037738b015ff430ec2b2caa091c44a51 Mon Sep 17 00:00:00 2001
From: Glen Davies <glen.davies@a8c.com>
Date: Fri, 5 Nov 2021 16:57:24 +1300
Subject: [PATCH] Add guards for undefined indexes

---
 packages/block-library/src/gallery/index.php | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/packages/block-library/src/gallery/index.php b/packages/block-library/src/gallery/index.php
index 1e5b21e067c66d..74ac0e3b96946a 100644
--- a/packages/block-library/src/gallery/index.php
+++ b/packages/block-library/src/gallery/index.php
@@ -21,7 +21,7 @@ function render_block_core_gallery_data( $parsed_block ) {
 	if ( 'core/gallery' === $parsed_block['blockName'] ) {
 		foreach ( $parsed_block['innerBlocks'] as $key => $inner_block ) {
 			if ( 'core/image' === $inner_block['blockName'] ) {
-				if ( ! $parsed_block['innerBlocks'][ $key ]['attrs']['data-id'] ) {
+				if ( ! isset( $parsed_block['innerBlocks'][ $key ]['attrs']['data-id'] ) && isset( $inner_block['attrs']['id'] ) ) {
 					$parsed_block['innerBlocks'][ $key ]['attrs']['data-id'] = esc_attr( $inner_block['attrs']['id'] );
 				}
 			}