Query: Ensure that the `page` parameter is scalar in `WP_Query::get_posts()`.

The `page` query var only accepts a scalar value and passes the value through functions that assume a scalar value.

Adding an extra guard condition does not affect its functionality but does avoid a PHP fatal error for `trim()` when a non-scalar value such as an array is passed.

Follow-up to [2535], [53891].

Props brookedot, rlmc, mukesh27, SergeyBiryukov.
Fixes #56558.
Built from https://develop.svn.wordpress.org/trunk@56815


git-svn-id: http://core.svn.wordpress.org/trunk@56327 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-includes/class-wp-query.php

@@ -2020,8 +2020,7 @@ class WP_Query {
 		}
 
 		if ( isset( $q['page'] ) ) {
-			$q['page'] = trim( $q['page'], '/' );
-			$q['page'] = absint( $q['page'] );
+			$q['page'] = is_scalar( $q['page'] ) ? absint( trim( $q['page'], '/' ) ) : 0;
 		}
 
 		// If true, forcibly turns off SQL_CALC_FOUND_ROWS even when limits are present.

wp-includes/version.php

@@ -16,7 +16,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '6.4-beta2-56814';
+$wp_version = '6.4-beta2-56815';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.