X-Git-Url: https://scripts.mit.edu/gitweb/autoinstalls/wordpress.git/blobdiff_plain/256a3b381f63716209b3527d0a14442ae570c283..refs/tags/wordpress-4.0:/wp-includes/meta.php?ds=sidebyside

diff --git a/wp-includes/meta.php b/wp-includes/meta.php
index 55beadb1..e3c43cff 100644
--- a/wp-includes/meta.php
+++ b/wp-includes/meta.php
@@ -16,8 +16,6 @@
  *
  * @since 2.9.0
  * @uses $wpdb WordPress database object for queries.
- * @uses do_action() Calls 'added_{$meta_type}_meta' with meta_id of added metadata entry,
- * 		object ID, meta key, and meta value
  *
  * @param string $meta_type Type of object metadata is for (e.g., comment, post, or user)
  * @param int $object_id ID of the object metadata is for
@@ -26,19 +24,24 @@
  * @param bool $unique Optional, default is false. Whether the specified metadata key should be
  * 		unique for the object. If true, and the object already has a value for the specified
  * 		metadata key, no change will be made
- * @return int|bool The meta ID on successful update, false on failure.
+ * @return int|bool The meta ID on success, false on failure.
  */
 function add_metadata($meta_type, $object_id, $meta_key, $meta_value, $unique = false) {
-	if ( !$meta_type || !$meta_key )
-		return false;
+	global $wpdb;
 
-	if ( !$object_id = absint($object_id) )
+	if ( ! $meta_type || ! $meta_key || ! is_numeric( $object_id ) ) {
 		return false;
+	}
 
-	if ( ! $table = _get_meta_table($meta_type) )
+	$object_id = absint( $object_id );
+	if ( ! $object_id ) {
 		return false;
+	}
 
-	global $wpdb;
+	$table = _get_meta_table( $meta_type );
+	if ( ! $table ) {
+		return false;
+	}
 
 	$column = sanitize_key($meta_type . '_id');
 
@@ -47,6 +50,22 @@ function add_metadata($meta_type, $object_id, $meta_key, $meta_value, $unique =
 	$meta_value = wp_unslash($meta_value);
 	$meta_value = sanitize_meta( $meta_key, $meta_value, $meta_type );
 
+	/**
+	 * Filter whether to add metadata of a specific type.
+	 *
+	 * The dynamic portion of the hook, $meta_type, refers to the meta
+	 * object type (comment, post, or user). Returning a non-null value
+	 * will effectively short-circuit the function.
+	 *
+	 * @since 3.1.0
+	 *
+	 * @param null|bool $check      Whether to allow adding metadata for the given type.
+	 * @param int       $object_id  Object ID.
+	 * @param string    $meta_key   Meta key.
+	 * @param mixed     $meta_value Meta value. Must be serializable if non-scalar.
+	 * @param bool      $unique     Whether the specified meta key should be unique
+	 *                              for the object. Optional. Default false.
+	 */
 	$check = apply_filters( "add_{$meta_type}_metadata", null, $object_id, $meta_key, $meta_value, $unique );
 	if ( null !== $check )
 		return $check;
@@ -59,6 +78,18 @@ function add_metadata($meta_type, $object_id, $meta_key, $meta_value, $unique =
 	$_meta_value = $meta_value;
 	$meta_value = maybe_serialize( $meta_value );
 
+	/**
+	 * Fires immediately before meta of a specific type is added.
+	 *
+	 * The dynamic portion of the hook, $meta_type, refers to the meta
+	 * object type (comment, post, or user).
+	 *
+	 * @since 3.1.0
+	 *
+	 * @param int    $object_id  Object ID.
+	 * @param string $meta_key   Meta key.
+	 * @param mixed  $meta_value Meta value.
+	 */
 	do_action( "add_{$meta_type}_meta", $object_id, $meta_key, $_meta_value );
 
 	$result = $wpdb->insert( $table, array(
@@ -74,6 +105,19 @@ function add_metadata($meta_type, $object_id, $meta_key, $meta_value, $unique =
 
 	wp_cache_delete($object_id, $meta_type . '_meta');
 
+	/**
+	 * Fires immediately after meta of a specific type is added.
+	 *
+	 * The dynamic portion of the hook, $meta_type, refers to the meta
+	 * object type (comment, post, or user).
+	 *
+	 * @since 2.9.0
+	 *
+	 * @param int    $mid        The meta ID after successful update.
+	 * @param int    $object_id  Object ID.
+	 * @param string $meta_key   Meta key.
+	 * @param mixed  $meta_value Meta value.
+	 */
 	do_action( "added_{$meta_type}_meta", $mid, $object_id, $meta_key, $_meta_value );
 
 	return $mid;
@@ -85,10 +129,6 @@ function add_metadata($meta_type, $object_id, $meta_key, $meta_value, $unique =
  *
  * @since 2.9.0
  * @uses $wpdb WordPress database object for queries.
- * @uses do_action() Calls 'update_{$meta_type}_meta' before updating metadata with meta_id of
- * 		metadata entry to update, object ID, meta key, and meta value
- * @uses do_action() Calls 'updated_{$meta_type}_meta' after updating metadata with meta_id of
- * 		updated metadata entry, object ID, meta key, and meta value
  *
  * @param string $meta_type Type of object metadata is for (e.g., comment, post, or user)
  * @param int $object_id ID of the object metadata is for
@@ -96,19 +136,24 @@ function add_metadata($meta_type, $object_id, $meta_key, $meta_value, $unique =
  * @param mixed $meta_value Metadata value. Must be serializable if non-scalar.
  * @param mixed $prev_value Optional. If specified, only update existing metadata entries with
  * 		the specified value. Otherwise, update all entries.
- * @return bool True on successful update, false on failure.
+ * @return int|bool Meta ID if the key didn't exist, true on successful update, false on failure.
  */
 function update_metadata($meta_type, $object_id, $meta_key, $meta_value, $prev_value = '') {
-	if ( !$meta_type || !$meta_key )
-		return false;
+	global $wpdb;
 
-	if ( !$object_id = absint($object_id) )
+	if ( ! $meta_type || ! $meta_key || ! is_numeric( $object_id ) ) {
 		return false;
+	}
 
-	if ( ! $table = _get_meta_table($meta_type) )
+	$object_id = absint( $object_id );
+	if ( ! $object_id ) {
 		return false;
+	}
 
-	global $wpdb;
+	$table = _get_meta_table( $meta_type );
+	if ( ! $table ) {
+		return false;
+	}
 
 	$column = sanitize_key($meta_type . '_id');
 	$id_column = 'user' == $meta_type ? 'umeta_id' : 'meta_id';
@@ -119,6 +164,23 @@ function update_metadata($meta_type, $object_id, $meta_key, $meta_value, $prev_v
 	$meta_value = wp_unslash($meta_value);
 	$meta_value = sanitize_meta( $meta_key, $meta_value, $meta_type );
 
+	/**
+	 * Filter whether to update metadata of a specific type.
+	 *
+	 * The dynamic portion of the hook, $meta_type, refers to the meta
+	 * object type (comment, post, or user). Returning a non-null value
+	 * will effectively short-circuit the function.
+	 *
+	 * @since 3.1.0
+	 *
+	 * @param null|bool $check      Whether to allow updating metadata for the given type.
+	 * @param int       $object_id  Object ID.
+	 * @param string    $meta_key   Meta key.
+	 * @param mixed     $meta_value Meta value. Must be serializable if non-scalar.
+	 * @param mixed     $prev_value Optional. If specified, only update existing
+	 *                              metadata entries with the specified value.
+	 *                              Otherwise, update all entries.
+	 */
 	$check = apply_filters( "update_{$meta_type}_metadata", null, $object_id, $meta_key, $meta_value, $prev_value );
 	if ( null !== $check )
 		return (bool) $check;
@@ -146,9 +208,32 @@ function update_metadata($meta_type, $object_id, $meta_key, $meta_value, $prev_v
 		$where['meta_value'] = $prev_value;
 	}
 
+	/**
+	 * Fires immediately before updating metadata of a specific type.
+	 *
+	 * The dynamic portion of the hook, $meta_type, refers to the meta
+	 * object type (comment, post, or user).
+	 *
+	 * @since 2.9.0
+	 *
+	 * @param int    $meta_id    ID of the metadata entry to update.
+	 * @param int    $object_id  Object ID.
+	 * @param string $meta_key   Meta key.
+	 * @param mixed  $meta_value Meta value.
+	 */
 	do_action( "update_{$meta_type}_meta", $meta_id, $object_id, $meta_key, $_meta_value );
 
 	if ( 'post' == $meta_type )
+		/**
+		 * Fires immediately before updating a post's metadata.
+		 *
+		 * @since 2.9.0
+		 *
+		 * @param int    $meta_id    ID of metadata entry to update.
+		 * @param int    $object_id  Object ID.
+		 * @param string $meta_key   Meta key.
+		 * @param mixed  $meta_value Meta value.
+		 */
 		do_action( 'update_postmeta', $meta_id, $object_id, $meta_key, $meta_value );
 
 	$result = $wpdb->update( $table, $data, $where );
@@ -157,10 +242,34 @@ function update_metadata($meta_type, $object_id, $meta_key, $meta_value, $prev_v
 
 	wp_cache_delete($object_id, $meta_type . '_meta');
 
+	/**
+	 * Fires immediately after updating metadata of a specific type.
+	 *
+	 * The dynamic portion of the hook, $meta_type, refers to the meta
+	 * object type (comment, post, or user).
+	 *
+	 * @since 2.9.0
+	 *
+	 * @param int    $meta_id    ID of updated metadata entry.
+	 * @param int    $object_id  Object ID.
+	 * @param string $meta_key   Meta key.
+	 * @param mixed  $meta_value Meta value.
+	 */
 	do_action( "updated_{$meta_type}_meta", $meta_id, $object_id, $meta_key, $_meta_value );
 
-	if ( 'post' == $meta_type )
+	if ( 'post' == $meta_type ) {
+		/**
+		 * Fires immediately after updating a post's metadata.
+		 *
+		 * @since 2.9.0
+		 *
+		 * @param int    $meta_id    ID of updated metadata entry.
+		 * @param int    $object_id  Object ID.
+		 * @param string $meta_key   Meta key.
+		 * @param mixed  $meta_value Meta value.
+		 */
 		do_action( 'updated_postmeta', $meta_id, $object_id, $meta_key, $meta_value );
+	}
 
 	return true;
 }
@@ -170,8 +279,6 @@ function update_metadata($meta_type, $object_id, $meta_key, $meta_value, $prev_v
  *
  * @since 2.9.0
  * @uses $wpdb WordPress database object for queries.
- * @uses do_action() Calls 'deleted_{$meta_type}_meta' after deleting with meta_id of
- * 		deleted metadata entries, object ID, meta key, and meta value
  *
  * @param string $meta_type Type of object metadata is for (e.g., comment, post, or user)
  * @param int $object_id ID of the object metadata is for
@@ -184,16 +291,21 @@ function update_metadata($meta_type, $object_id, $meta_key, $meta_value, $prev_v
  * @return bool True on successful delete, false on failure.
  */
 function delete_metadata($meta_type, $object_id, $meta_key, $meta_value = '', $delete_all = false) {
-	if ( !$meta_type || !$meta_key )
-		return false;
+	global $wpdb;
 
-	if ( (!$object_id = absint($object_id)) && !$delete_all )
+	if ( ! $meta_type || ! $meta_key || ! is_numeric( $object_id ) && ! $delete_all ) {
 		return false;
+	}
 
-	if ( ! $table = _get_meta_table($meta_type) )
+	$object_id = absint( $object_id );
+	if ( ! $object_id && ! $delete_all ) {
 		return false;
+	}
 
-	global $wpdb;
+	$table = _get_meta_table( $meta_type );
+	if ( ! $table ) {
+		return false;
+	}
 
 	$type_column = sanitize_key($meta_type . '_id');
 	$id_column = 'user' == $meta_type ? 'umeta_id' : 'meta_id';
@@ -201,6 +313,23 @@ function delete_metadata($meta_type, $object_id, $meta_key, $meta_value = '', $d
 	$meta_key = wp_unslash($meta_key);
 	$meta_value = wp_unslash($meta_value);
 
+	/**
+	 * Filter whether to delete metadata of a specific type.
+	 *
+	 * The dynamic portion of the hook, $meta_type, refers to the meta
+	 * object type (comment, post, or user). Returning a non-null value
+	 * will effectively short-circuit the function.
+	 *
+	 * @since 3.1.0
+	 *
+	 * @param null|bool $delete     Whether to allow metadata deletion of the given type.
+	 * @param int       $object_id  Object ID.
+	 * @param string    $meta_key   Meta key.
+	 * @param mixed     $meta_value Meta value. Must be serializable if non-scalar.
+	 * @param bool      $delete_all Whether to delete the matching metadata entries
+	 *                              for all objects, ignoring the specified $object_id.
+	 *                              Default false.
+	 */
 	$check = apply_filters( "delete_{$meta_type}_metadata", null, $object_id, $meta_key, $meta_value, $delete_all );
 	if ( null !== $check )
 		return (bool) $check;
@@ -223,11 +352,32 @@ function delete_metadata($meta_type, $object_id, $meta_key, $meta_value = '', $d
 	if ( $delete_all )
 		$object_ids = $wpdb->get_col( $wpdb->prepare( "SELECT $type_column FROM $table WHERE meta_key = %s", $meta_key ) );
 
+	/**
+	 * Fires immediately before deleting metadata of a specific type.
+	 *
+	 * The dynamic portion of the hook, $meta_type, refers to the meta
+	 * object type (comment, post, or user).
+	 *
+	 * @since 3.1.0
+	 *
+	 * @param array  $meta_ids   An array of metadata entry IDs to delete.
+	 * @param int    $object_id  Object ID.
+	 * @param string $meta_key   Meta key.
+	 * @param mixed  $meta_value Meta value.
+	 */
 	do_action( "delete_{$meta_type}_meta", $meta_ids, $object_id, $meta_key, $_meta_value );
 
 	// Old-style action.
-	if ( 'post' == $meta_type )
+	if ( 'post' == $meta_type ) {
+		/**
+		 * Fires immediately before deleting metadata for a post.
+		 *
+		 * @since 2.9.0
+		 *
+		 * @param array $meta_ids An array of post metadata entry IDs to delete.
+		 */
 		do_action( 'delete_postmeta', $meta_ids );
+	}
 
 	$query = "DELETE FROM $table WHERE $id_column IN( " . implode( ',', $meta_ids ) . " )";
 
@@ -244,11 +394,32 @@ function delete_metadata($meta_type, $object_id, $meta_key, $meta_value = '', $d
 		wp_cache_delete($object_id, $meta_type . '_meta');
 	}
 
+	/**
+	 * Fires immediately after deleting metadata of a specific type.
+	 *
+	 * The dynamic portion of the hook name, $meta_type, refers to the meta
+	 * object type (comment, post, or user).
+	 *
+	 * @since 2.9.0
+	 *
+	 * @param array  $meta_ids   An array of deleted metadata entry IDs.
+	 * @param int    $object_id  Object ID.
+	 * @param string $meta_key   Meta key.
+	 * @param mixed  $meta_value Meta value.
+	 */
 	do_action( "deleted_{$meta_type}_meta", $meta_ids, $object_id, $meta_key, $_meta_value );
 
 	// Old-style action.
-	if ( 'post' == $meta_type )
+	if ( 'post' == $meta_type ) {
+		/**
+		 * Fires immediately after deleting metadata for a post.
+		 *
+		 * @since 2.9.0
+		 *
+		 * @param array $meta_ids An array of deleted post metadata entry IDs.
+		 */
 		do_action( 'deleted_postmeta', $meta_ids );
+	}
 
 	return true;
 }
@@ -267,12 +438,31 @@ function delete_metadata($meta_type, $object_id, $meta_key, $meta_value = '', $d
  * @return string|array Single metadata value, or array of values
  */
 function get_metadata($meta_type, $object_id, $meta_key = '', $single = false) {
-	if ( !$meta_type )
+	if ( ! $meta_type || ! is_numeric( $object_id ) ) {
 		return false;
+	}
 
-	if ( !$object_id = absint($object_id) )
+	$object_id = absint( $object_id );
+	if ( ! $object_id ) {
 		return false;
+	}
 
+	/**
+	 * Filter whether to retrieve metadata of a specific type.
+	 *
+	 * The dynamic portion of the hook, $meta_type, refers to the meta
+	 * object type (comment, post, or user). Returning a non-null value
+	 * will effectively short-circuit the function.
+	 *
+	 * @since 3.1.0
+	 *
+	 * @param null|array|string $value     The value get_metadata() should
+	 *                                     return - a single metadata value,
+	 *                                     or an array of values.
+	 * @param int               $object_id Object ID.
+	 * @param string            $meta_key  Meta key.
+	 * @param string|array      $single    Meta value, or an array of values.
+	 */
 	$check = apply_filters( "get_{$meta_type}_metadata", null, $object_id, $meta_key, $single );
 	if ( null !== $check ) {
 		if ( $single && is_array( $check ) )
@@ -315,15 +505,19 @@ function get_metadata($meta_type, $object_id, $meta_key = '', $single = false) {
  * @return boolean true of the key is set, false if not.
  */
 function metadata_exists( $meta_type, $object_id, $meta_key ) {
-	if ( ! $meta_type )
+	if ( ! $meta_type || ! is_numeric( $object_id ) ) {
 		return false;
+	}
 
-	if ( ! $object_id = absint( $object_id ) )
+	$object_id = absint( $object_id );
+	if ( ! $object_id ) {
 		return false;
+	}
 
+	/** This filter is documented in wp-includes/meta.php */
 	$check = apply_filters( "get_{$meta_type}_metadata", null, $object_id, $meta_key, true );
 	if ( null !== $check )
-		return true;
+		return (bool) $check;
 
 	$meta_cache = wp_cache_get( $object_id, $meta_type . '_meta' );
 
@@ -350,14 +544,19 @@ function metadata_exists( $meta_type, $object_id, $meta_key ) {
 function get_metadata_by_mid( $meta_type, $meta_id ) {
 	global $wpdb;
 
-	if ( ! $meta_type )
+	if ( ! $meta_type || ! is_numeric( $meta_id ) ) {
 		return false;
+	}
 
-	if ( !$meta_id = absint( $meta_id ) )
+	$meta_id = absint( $meta_id );
+	if ( ! $meta_id ) {
 		return false;
+	}
 
-	if ( ! $table = _get_meta_table($meta_type) )
+	$table = _get_meta_table( $meta_type );
+	if ( ! $table ) {
 		return false;
+	}
 
 	$id_column = ( 'user' == $meta_type ) ? 'umeta_id' : 'meta_id';
 
@@ -390,14 +589,19 @@ function update_metadata_by_mid( $meta_type, $meta_id, $meta_value, $meta_key =
 	global $wpdb;
 
 	// Make sure everything is valid.
-	if ( ! $meta_type )
+	if ( ! $meta_type || ! is_numeric( $meta_id ) ) {
 		return false;
+	}
 
-	if ( ! $meta_id = absint( $meta_id ) )
+	$meta_id = absint( $meta_id );
+	if ( ! $meta_id ) {
 		return false;
+	}
 
-	if ( ! $table = _get_meta_table( $meta_type ) )
+	$table = _get_meta_table( $meta_type );
+	if ( ! $table ) {
 		return false;
+	}
 
 	$column = sanitize_key($meta_type . '_id');
 	$id_column = 'user' == $meta_type ? 'umeta_id' : 'meta_id';
@@ -405,7 +609,6 @@ function update_metadata_by_mid( $meta_type, $meta_id, $meta_value, $meta_key =
 	// Fetch the meta and go on if it's found.
 	if ( $meta = get_metadata_by_mid( $meta_type, $meta_id ) ) {
 		$original_key = $meta->meta_key;
-		$original_value = $meta->meta_value;
 		$object_id = $meta->{$column};
 
 		// If a new meta_key (last parameter) was specified, change the meta key,
@@ -431,10 +634,13 @@ function update_metadata_by_mid( $meta_type, $meta_id, $meta_value, $meta_key =
 		$where = array();
 		$where[$id_column] = $meta_id;
 
+		/** This action is documented in wp-includes/meta.php */
 		do_action( "update_{$meta_type}_meta", $meta_id, $object_id, $meta_key, $_meta_value );
 
-		if ( 'post' == $meta_type )
+		if ( 'post' == $meta_type ) {
+			/** This action is documented in wp-includes/meta.php */
 			do_action( 'update_postmeta', $meta_id, $object_id, $meta_key, $meta_value );
+		}
 
 		// Run the update query, all fields in $data are %s, $where is a %d.
 		$result = $wpdb->update( $table, $data, $where, '%s', '%d' );
@@ -444,10 +650,13 @@ function update_metadata_by_mid( $meta_type, $meta_id, $meta_value, $meta_key =
 		// Clear the caches.
 		wp_cache_delete($object_id, $meta_type . '_meta');
 
+		/** This action is documented in wp-includes/meta.php */
 		do_action( "updated_{$meta_type}_meta", $meta_id, $object_id, $meta_key, $_meta_value );
 
-		if ( 'post' == $meta_type )
+		if ( 'post' == $meta_type ) {
+			/** This action is documented in wp-includes/meta.php */
 			do_action( 'updated_postmeta', $meta_id, $object_id, $meta_key, $meta_value );
+		}
 
 		return true;
 	}
@@ -472,14 +681,19 @@ function delete_metadata_by_mid( $meta_type, $meta_id ) {
 	global $wpdb;
 
 	// Make sure everything is valid.
-	if ( ! $meta_type )
+	if ( ! $meta_type || ! is_numeric( $meta_id ) ) {
 		return false;
+	}
 
-	if ( ! $meta_id = absint( $meta_id ) )
+	$meta_id = absint( $meta_id );
+	if ( ! $meta_id ) {
 		return false;
+	}
 
-	if ( ! $table = _get_meta_table( $meta_type ) )
+	$table = _get_meta_table( $meta_type );
+	if ( ! $table ) {
 		return false;
+	}
 
 	// object and id columns
 	$column = sanitize_key($meta_type . '_id');
@@ -489,11 +703,23 @@ function delete_metadata_by_mid( $meta_type, $meta_id ) {
 	if ( $meta = get_metadata_by_mid( $meta_type, $meta_id ) ) {
 		$object_id = $meta->{$column};
 
+		/** This action is documented in wp-includes/meta.php */
 		do_action( "delete_{$meta_type}_meta", (array) $meta_id, $object_id, $meta->meta_key, $meta->meta_value );
 
 		// Old-style action.
-		if ( 'post' == $meta_type || 'comment' == $meta_type )
+		if ( 'post' == $meta_type || 'comment' == $meta_type ) {
+			/**
+			 * Fires immediately before deleting post or comment metadata of a specific type.
+			 *
+			 * The dynamic portion of the hook, $meta_type, refers to the meta
+			 * object type (post or comment).
+			 *
+			 * @since 3.4.0
+			 *
+			 * @param int $meta_id ID of the metadata entry to delete.
+			 */
 			do_action( "delete_{$meta_type}meta", $meta_id );
+		}
 
 		// Run the query, will return true if deleted, false otherwise
 		$result = (bool) $wpdb->delete( $table, array( $id_column => $meta_id ) );
@@ -501,11 +727,23 @@ function delete_metadata_by_mid( $meta_type, $meta_id ) {
 		// Clear the caches.
 		wp_cache_delete($object_id, $meta_type . '_meta');
 
+		/** This action is documented in wp-includes/meta.php */
 		do_action( "deleted_{$meta_type}_meta", (array) $meta_id, $object_id, $meta->meta_key, $meta->meta_value );
 
 		// Old-style action.
-		if ( 'post' == $meta_type || 'comment' == $meta_type )
+		if ( 'post' == $meta_type || 'comment' == $meta_type ) {
+			/**
+			 * Fires immediately after deleting post or comment metadata of a specific type.
+			 *
+			 * The dynamic portion of the hook, $meta_type, refers to the meta
+			 * object type (post or comment).
+			 *
+			 * @since 3.4.0
+			 *
+			 * @param int $meta_ids Deleted metadata entry ID.
+			 */
 			do_action( "deleted_{$meta_type}meta", $meta_id );
+		}
 
 		return $result;
 
@@ -526,16 +764,19 @@ function delete_metadata_by_mid( $meta_type, $meta_id ) {
  * @return mixed Metadata cache for the specified objects, or false on failure.
  */
 function update_meta_cache($meta_type, $object_ids) {
-	if ( empty( $meta_type ) || empty( $object_ids ) )
+	global $wpdb;
+
+	if ( ! $meta_type || ! $object_ids ) {
 		return false;
+	}
 
-	if ( ! $table = _get_meta_table($meta_type) )
+	$table = _get_meta_table( $meta_type );
+	if ( ! $table ) {
 		return false;
+	}
 
 	$column = sanitize_key($meta_type . '_id');
 
-	global $wpdb;
-
 	if ( !is_array($object_ids) ) {
 		$object_ids = preg_replace('|[^0-9,]|', '', $object_ids);
 		$object_ids = explode(',', $object_ids);
@@ -645,7 +886,7 @@ class WP_Meta_Query {
 	 *
 	 * @param array $meta_query (optional) A meta query
 	 */
-	function __construct( $meta_query = false ) {
+	public function __construct( $meta_query = false ) {
 		if ( !$meta_query )
 			return;
 
@@ -673,7 +914,7 @@ class WP_Meta_Query {
 	 *
 	 * @param array $qv The query variables
 	 */
-	function parse_query_vars( $qv ) {
+	public function parse_query_vars( $qv ) {
 		$meta_query = array();
 
 		// Simple query needs to be first for orderby=meta_value to work correctly
@@ -701,7 +942,7 @@ class WP_Meta_Query {
 	 * @param string $type MySQL type to cast meta_value
 	 * @return string MySQL type
 	 */
-	function get_cast_for_type( $type = '' ) {
+	public function get_cast_for_type( $type = '' ) {
 		if ( empty( $type ) )
 			return 'CHAR';
 
@@ -728,7 +969,7 @@ class WP_Meta_Query {
 	 * @param object $context (optional) The main query object
 	 * @return array( 'join' => $join_sql, 'where' => $where_sql )
 	 */
-	function get_sql( $type, $primary_table, $primary_id_column, $context = null ) {
+	public function get_sql( $type, $primary_table, $primary_id_column, $context = null ) {
 		global $wpdb;
 
 		if ( ! $meta_table = _get_meta_table( $type ) )
@@ -753,7 +994,7 @@ class WP_Meta_Query {
 		// Split out the meta_key only queries (we can only do this for OR)
 		if ( 'OR' == $this->relation ) {
 			foreach ( $this->queries as $k => $q ) {
-				if ( ! array_key_exists( 'value', $q ) && ! empty( $q['key'] ) )
+				if ( ( empty( $q['compare'] ) || 'NOT EXISTS' != $q['compare'] ) && ! array_key_exists( 'value', $q ) && ! empty( $q['key'] ) )
 					$key_only_queries[$k] = $q;
 				else
 					$queries[$k] = $q;
@@ -838,8 +1079,8 @@ class WP_Meta_Query {
 			} elseif ( 'BETWEEN' == substr( $meta_compare, -7) ) {
 				$meta_value = array_slice( $meta_value, 0, 2 );
 				$meta_compare_string = '%s AND %s';
-			} elseif ( 'LIKE' == substr( $meta_compare, -4 ) ) {
-				$meta_value = '%' . like_escape( $meta_value ) . '%';
+			} elseif ( 'LIKE' == $meta_compare || 'NOT LIKE' == $meta_compare ) {
+				$meta_value = '%' . $wpdb->esc_like( $meta_value ) . '%';
 				$meta_compare_string = '%s';
 			} else {
 				$meta_compare_string = '%s';
@@ -862,6 +1103,22 @@ class WP_Meta_Query {
 		if ( ! empty( $join ) )
 			$join = ' ' . $join;
 
+		/**
+		 * Filter the meta query's generated SQL.
+		 *
+		 * @since 3.1.0
+		 *
+		 * @param array $args {
+		 *     An array of arguments.
+		 *
+		 *     @type array  $clauses           Array containing the query's JOIN and WHERE clauses.
+		 *     @type array  $queries           Array of meta queries.
+		 *     @type string $type              Type of meta.
+		 *     @type string $primary_table     Primary table.
+		 *     @type string $primary_id_column Primary column ID.
+		 *     @type object $context           The main query object.
+		 * }
+		 */
 		return apply_filters_ref_array( 'get_meta_sql', array( compact( 'join', 'where' ), $this->queries, $type, $primary_table, $primary_id_column, $context ) );
 	}
 }
@@ -887,7 +1144,7 @@ function _get_meta_table($type) {
 }
 
 /**
- * Determine whether a meta key is protected
+ * Determine whether a meta key is protected.
  *
  * @since 3.1.3
  *
@@ -897,11 +1154,20 @@ function _get_meta_table($type) {
 function is_protected_meta( $meta_key, $meta_type = null ) {
 	$protected = ( '_' == $meta_key[0] );
 
+	/**
+	 * Filter whether a meta key is protected.
+	 *
+	 * @since 3.2.0
+	 *
+	 * @param bool   $protected Whether the key is protected. Default false.
+	 * @param string $meta_key  Meta key.
+	 * @param string $meta_type Meta type.
+	 */
 	return apply_filters( 'is_protected_meta', $protected, $meta_key, $meta_type );
 }
 
 /**
- * Sanitize meta value
+ * Sanitize meta value.
  *
  * @since 3.1.3
  *
@@ -911,6 +1177,20 @@ function is_protected_meta( $meta_key, $meta_type = null ) {
  * @return mixed Sanitized $meta_value
  */
 function sanitize_meta( $meta_key, $meta_value, $meta_type ) {
+
+	/**
+	 * Filter the sanitization of a specific meta key of a specific meta type.
+	 *
+	 * The dynamic portions of the hook name, $meta_type and $meta_key, refer to the
+	 * metadata object type (comment, post, or user) and the meta key value,
+	 * respectively.
+	 *
+	 * @since 3.3.0
+	 *
+	 * @param mixed  $meta_value Meta value to sanitize.
+	 * @param string $meta_key   Meta key.
+	 * @param string $meta_type  Meta type.
+	 */
 	return apply_filters( "sanitize_{$meta_type}_meta_{$meta_key}", $meta_value, $meta_key, $meta_type );
 }