Add a safe guard that the variable is set before accessing it (#11424)

Author: kmanijak

src/BlockTypes/ProductTemplate.php

@@ -61,7 +61,7 @@ protected function render( $attributes, $content, $block ) {
 		$classnames = '';
 		if ( isset( $block->context['displayLayout'] ) && isset( $block->context['query'] ) ) {
 			if ( isset( $block->context['displayLayout']['type'] ) && 'flex' === $block->context['displayLayout']['type'] ) {
-				if ( $block->context['displayLayout']['shrinkColumns'] ) {
+				if ( isset( $block->context['displayLayout']['shrinkColumns'] ) && $block->context['displayLayout']['shrinkColumns'] ) {
 					$classnames = "wc-block-product-template__responsive columns-{$block->context['displayLayout']['columns']}";
 				} else {
 					$classnames = "is-flex-container columns-{$block->context['displayLayout']['columns']}";