Infinite scroll added checks to validate input (#39618)

* Added isset checks to avoid Warnings

* changelog

* Added new isset for last_post_date

* Deprecate infinite_scroll_posts_where  hook

projects/plugins/jetpack/changelog/update-infinite-scroll-added-checks-to-validate-input

@@ -0,0 +1,4 @@
+Significance: minor
+Type: other
+
+Infinite-scroll: Added isset checks to validate input data

projects/plugins/jetpack/modules/infinite-scroll/infinity.php

@@ -753,11 +753,12 @@ public function query_time_filter( $where, $query ) {
 
 			$sort_field = self::get_query_sort_field( $query );
 
-			if ( 'post_date' !== $sort_field || 'DESC' !== $_REQUEST['query_args']['order'] ) { // phpcs:ignore WordPress.Security.NonceVerification.Recommended, WordPress.Security.ValidatedSanitizedInput.InputNotValidated -- no changes made to the site.
+			if ( 'post_date' !== $sort_field ||
+			! isset( $_REQUEST['query_args']['order'] ) || 'DESC' !== $_REQUEST['query_args']['order'] ) { // phpcs:ignore WordPress.Security.NonceVerification.Recommended -- no changes made to the site.
 				return $where;
 			}
 
-			$query_before = sanitize_text_field( wp_unslash( $_REQUEST['query_before'] ) ); // phpcs:ignore WordPress.Security.NonceVerification.Recommended, WordPress.Security.ValidatedSanitizedInput.InputNotValidated -- no changes made to the site.
+			$query_before = isset( $_REQUEST['query_before'] ) ? sanitize_text_field( wp_unslash( $_REQUEST['query_before'] ) ) : ''; // phpcs:ignore WordPress.Security.NonceVerification.Recommended -- no changes made to the site.
 
 			if ( empty( $query_before ) ) {
 				return $where;
@@ -771,16 +772,18 @@ public function query_time_filter( $where, $query ) {
 			 * will always return results prior to (descending sort)
 			 * or before (ascending sort) the last post date.
 			 *
+			 * @deprecated $$next-version$$
+			 *
 			 * @module infinite-scroll
 			 *
 			 * @param string $clause SQL Date query.
 			 * @param object $query Query.
 			 * @param string $operator @deprecated Query operator.
 			 * @param string $last_post_date @deprecated Last Post Date timestamp.
 			 */
-			$operator       = 'ASC' === $_REQUEST['query_args']['order'] ? '>' : '<'; // phpcs:ignore WordPress.Security.NonceVerification.Recommended, WordPress.Security.ValidatedSanitizedInput.InputNotValidated -- no changes to the site.
-			$last_post_date = sanitize_text_field( wp_unslash( $_REQUEST['last_post_date'] ) ); // phpcs:ignore WordPress.Security.NonceVerification.Recommended, WordPress.Security.ValidatedSanitizedInput.InputNotValidated -- no changes to the site.
-			$where         .= apply_filters( 'infinite_scroll_posts_where', $clause, $query, $operator, $last_post_date );
+			$operator       = '<';
+			$last_post_date = isset( $_REQUEST['last_post_date'] ) ? sanitize_text_field( wp_unslash( $_REQUEST['last_post_date'] ) ) : ''; // phpcs:ignore WordPress.Security.NonceVerification.Recommended -- no changes to the site
+			$where         .= apply_filters_deprecated( 'infinite_scroll_posts_where', array( $clause, $query, $operator, $last_post_date ), '$$next-version$$', '' );
 		}
 
 		return $where;