Query: Revert [55169].

Revert [55169] and mark #56689 as wontfix. `get_page_by_path` can not use `WP_Query`, as is results in fatel errors for those using `get_page_by_path` in the `pre_get_posts` action or `posts_pre_query` filter. This sadly means that `WP_Query` can never be used in `get_page_by_path`.

Props spacedmonkey, iandunn, mukesh27, joemcgill, adamsilverstein, otto42. 
See #56689.

git-svn-id: https://develop.svn.wordpress.org/trunk@55215 602fd350-edb4-49c9-b593-d223f7449a82

src/wp-includes/post.php

@@ -5675,6 +5675,8 @@ function get_page( $page, $output = OBJECT, $filter = 'raw' ) {
  *
  * @since 2.1.0
  *
+ * @global wpdb $wpdb WordPress database abstraction object.
+ *
  * @param string       $page_path Page path.
  * @param string       $output    Optional. The required return type. One of OBJECT, ARRAY_A, or ARRAY_N, which
  *                                correspond to a WP_Post object, an associative array, or a numeric array,
@@ -5683,41 +5685,52 @@ function get_page( $page, $output = OBJECT, $filter = 'raw' ) {
  * @return WP_Post|array|null WP_Post (or array) on success, or null on failure.
  */
 function get_page_by_path( $page_path, $output = OBJECT, $post_type = 'page' ) {
-	$page_path = rawurlencode( urldecode( $page_path ) );
-	$page_path = str_replace( '%2F', '/', $page_path );
-	$page_path = str_replace( '%20', ' ', $page_path );
-	$parts     = explode( '/', trim( $page_path, '/' ) );
-	$parts     = array_map( 'sanitize_title_for_query', $parts );
+	global $wpdb;
+
+	$last_changed = wp_cache_get_last_changed( 'posts' );
+
+	$hash      = md5( $page_path . serialize( $post_type ) );
+	$cache_key = "get_page_by_path:$hash:$last_changed";
+	$cached    = wp_cache_get( $cache_key, 'posts' );
+	if ( false !== $cached ) {
+		// Special case: '0' is a bad `$page_path`.
+		if ( '0' === $cached || 0 === $cached ) {
+			return;
+		} else {
+			return get_post( $cached, $output );
+		}
+	}
+
+	$page_path     = rawurlencode( urldecode( $page_path ) );
+	$page_path     = str_replace( '%2F', '/', $page_path );
+	$page_path     = str_replace( '%20', ' ', $page_path );
+	$parts         = explode( '/', trim( $page_path, '/' ) );
+	$parts         = array_map( 'sanitize_title_for_query', $parts );
+	$escaped_parts = esc_sql( $parts );
+
+	$in_string = "'" . implode( "','", $escaped_parts ) . "'";
 
 	if ( is_array( $post_type ) ) {
 		$post_types = $post_type;
 	} else {
 		$post_types = array( $post_type, 'attachment' );
 	}
 
-	$args = array(
-		'post_name__in'          => $parts,
-		'post_type'              => $post_types,
-		'post_status'            => 'all',
-		'posts_per_page'         => -1,
-		'update_post_term_cache' => false,
-		'update_post_meta_cache' => false,
-		'no_found_rows'          => true,
-		'orderby'                => 'none',
-	);
+	$post_types          = esc_sql( $post_types );
+	$post_type_in_string = "'" . implode( "','", $post_types ) . "'";
+	$sql                 = "
+		SELECT ID, post_name, post_parent, post_type
+		FROM $wpdb->posts
+		WHERE post_name IN ($in_string)
+		AND post_type IN ($post_type_in_string)
+	";
 
-	$query = new WP_Query( $args );
-	$posts = $query->get_posts();
-	$pages = array();
-
-	foreach ( $posts as $post ) {
-		$pages[ $post->ID ] = $post;
-	}
+	$pages = $wpdb->get_results( $sql, OBJECT_K );
 
 	$revparts = array_reverse( $parts );
 
 	$foundid = 0;
-	foreach ( $pages as $page ) {
+	foreach ( (array) $pages as $page ) {
 		if ( $page->post_name == $revparts[0] ) {
 			$count = 0;
 			$p     = $page;
@@ -5744,6 +5757,9 @@ function get_page_by_path( $page_path, $output = OBJECT, $post_type = 'page' ) {
 		}
 	}
 
+	// We cache misses as well as hits.
+	wp_cache_set( $cache_key, $foundid, 'posts' );
+
 	if ( $foundid ) {
 		return get_post( $foundid, $output );
 	}