Classes that have `__set()` also need `__isset()` and `__unset()`.

See #27881, #22234.

Built from https://develop.svn.wordpress.org/trunk@28524


git-svn-id: http://core.svn.wordpress.org/trunk@28350 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-admin/custom-background.php

@@ -81,6 +81,27 @@ class Custom_Background {
 		return $this->$name = $value;
 	}
 
+	/**
+	 * Make private properties checkable for backwards compatibility
+	 *
+	 * @since 4.0.0
+	 * @param string $name
+	 * @return mixed
+	 */
+	public function __isset( $name ) {
+		return isset( $this->$name );
+	}
+
+	/**
+	 * Make private properties unsetable for backwards compatibility
+	 *
+	 * @since 4.0.0
+	 * @param string $name
+	 * @return mixed
+	 */
+	public function __unset( $name ) {
+		unset( $this->$name );
+	}
 
 	/**
 	 * Set up the hooks for the Custom Background admin page.

wp-admin/custom-header.php

@@ -103,6 +103,28 @@ class Custom_Image_Header {
 		return $this->$name = $value;
 	}
 
+	/**
+	 * Make private properties checkable for backwards compatibility
+	 *
+	 * @since 4.0.0
+	 * @param string $name
+	 * @return mixed
+	 */
+	public function __isset( $name ) {
+		return isset( $this->$name );
+	}
+
+	/**
+	 * Make private properties unsetable for backwards compatibility
+	 *
+	 * @since 4.0.0
+	 * @param string $name
+	 * @return mixed
+	 */
+	public function __unset( $name ) {
+		unset( $this->$name );
+	}
+
 	/**
 	 * Set up the hooks for the Custom Header admin page.
 	 *

wp-admin/includes/class-wp-filesystem-base.php

@@ -67,6 +67,28 @@ class WP_Filesystem_Base {
 		return $this->$name = $value;
 	}
 
+	/**
+	 * Make private properties checkable for backwards compatibility
+	 *
+	 * @since 4.0.0
+	 * @param string $name
+	 * @return mixed
+	 */
+	public function __isset( $name ) {
+		return isset( $this->$name );
+	}
+
+	/**
+	 * Make private properties unsetable for backwards compatibility
+	 *
+	 * @since 4.0.0
+	 * @param string $name
+	 * @return mixed
+	 */
+	public function __unset( $name ) {
+		unset( $this->$name );
+	}
+
 	/**
 	 * Return the path on the remote filesystem of ABSPATH.
 	 *

wp-admin/includes/class-wp-list-table.php

@@ -118,6 +118,28 @@ class WP_List_Table {
 		return $this->$name = $value;
 	}
 
+	/**
+	 * Make private properties checkable for backwards compatibility
+	 *
+	 * @since 4.0.0
+	 * @param string $name
+	 * @return mixed
+	 */
+	public function __isset( $name ) {
+		return isset( $this->$name );
+	}
+
+	/**
+	 * Make private properties unsetable for backwards compatibility
+	 *
+	 * @since 4.0.0
+	 * @param string $name
+	 * @return mixed
+	 */
+	public function __unset( $name ) {
+		unset( $this->$name );
+	}
+
 	/**
 	 * Make private/protected methods readable for backwards compatibility
 	 *

wp-includes/cache.php

@@ -329,6 +329,28 @@ class WP_Object_Cache {
 		return $this->$name = $value;
 	}
 
+	/**
+	 * Make private properties checkable for backwards compatibility
+	 *
+	 * @since 4.0.0
+	 * @param string $name
+	 * @return mixed
+	 */
+	public function __isset( $name ) {
+		return isset( $this->$name );
+	}
+
+	/**
+	 * Make private properties unsetable for backwards compatibility
+	 *
+	 * @since 4.0.0
+	 * @param string $name
+	 * @return mixed
+	 */
+	public function __unset( $name ) {
+		unset( $this->$name );
+	}
+
 	/**
 	 * Adds data to the cache if it doesn't already exist.
 	 *

wp-includes/class-wp-ajax-response.php

@@ -52,6 +52,28 @@ class WP_Ajax_Response {
 		return $this->$name = $value;
 	}
 
+	/**
+	 * Make private properties checkable for backwards compatibility
+	 *
+	 * @since 4.0.0
+	 * @param string $name
+	 * @return mixed
+	 */
+	public function __isset( $name ) {
+		return isset( $this->$name );
+	}
+
+	/**
+	 * Make private properties unsetable for backwards compatibility
+	 *
+	 * @since 4.0.0
+	 * @param string $name
+	 * @return mixed
+	 */
+	public function __unset( $name ) {
+		unset( $this->$name );
+	}
+
 	/**
 	 * Append to XML response based on given arguments.
 	 *

wp-includes/class-wp-error.php

@@ -87,6 +87,28 @@ class WP_Error {
 		return $this->$name = $value;
 	}
 
+	/**
+	 * Make private properties checkable for backwards compatibility
+	 *
+	 * @since 4.0.0
+	 * @param string $name
+	 * @return mixed
+	 */
+	public function __isset( $name ) {
+		return isset( $this->$name );
+	}
+
+	/**
+	 * Make private properties unsetable for backwards compatibility
+	 *
+	 * @since 4.0.0
+	 * @param string $name
+	 * @return mixed
+	 */
+	public function __unset( $name ) {
+		unset( $this->$name );
+	}
+
 	/**
 	 * Retrieve all error codes.
 	 *

wp-includes/class-wp-walker.php

@@ -62,6 +62,28 @@ class Walker {
 		return $this->$name = $value;
 	}
 
+	/**
+	 * Make private properties checkable for backwards compatibility
+	 *
+	 * @since 4.0.0
+	 * @param string $name
+	 * @return mixed
+	 */
+	public function __isset( $name ) {
+		return isset( $this->$name );
+	}
+
+	/**
+	 * Make private properties unsetable for backwards compatibility
+	 *
+	 * @since 4.0.0
+	 * @param string $name
+	 * @return mixed
+	 */
+	public function __unset( $name ) {
+		unset( $this->$name );
+	}
+
 	/**
 	 * Starts the list before the elements are added.
 	 *

wp-includes/class-wp.php

@@ -685,6 +685,28 @@ class WP_MatchesMapRegex {
 		return $this->$name = $value;
 	}
 
+	/**
+	 * Make private properties checkable for backwards compatibility
+	 *
+	 * @since 4.0.0
+	 * @param string $name
+	 * @return mixed
+	 */
+	public function __isset( $name ) {
+		return isset( $this->$name );
+	}
+
+	/**
+	 * Make private properties unsetable for backwards compatibility
+	 *
+	 * @since 4.0.0
+	 * @param string $name
+	 * @return mixed
+	 */
+	public function __unset( $name ) {
+		unset( $this->$name );
+	}
+
 	/**
 	 * Make private/protected methods readable for backwards compatibility
 	 *