Prevent unintended behavior when certain objects are unserialized.

Props ehtis, xknown.

Built from https://develop.svn.wordpress.org/trunk@56835


git-svn-id: http://core.svn.wordpress.org/trunk@56347 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-includes/class-wp-theme.php

@@ -772,6 +772,28 @@ final class WP_Theme implements ArrayAccess {
 		return isset( $this->parent ) ? $this->parent : false;
 	}
 
+	/**
+	 * Perform reinitialization tasks.
+	 *
+	 * Prevents a callback from being injected during unserialization of an object.
+	 *
+	 * @return void
+	 */
+	public function __wakeup() {
+		if ( $this->parent && ! $this->parent instanceof self ) {
+			throw new UnexpectedValueException();
+		}
+		if ( $this->headers && ! is_array( $this->headers ) ) {
+			throw new UnexpectedValueException();
+		}
+		foreach ( $this->headers as $value ) {
+			if ( ! is_string( $value ) ) {
+				throw new UnexpectedValueException();
+			}
+		}
+		$this->headers_sanitized = array();
+	}
+
 	/**
 	 * Adds theme data to cache.
 	 *
@@ -1918,4 +1940,16 @@ final class WP_Theme implements ArrayAccess {
 	private static function _name_sort_i18n( $a, $b ) {
 		return strnatcasecmp( $a->name_translated, $b->name_translated );
 	}
+
+	private static function _check_headers_property_has_correct_type( $headers ) {
+		if ( ! is_array( $headers ) ) {
+			return false;
+		}
+		foreach ( $headers as $key => $value ) {
+			if ( ! is_string( $key ) || ! is_string( $value ) ) {
+				return false;
+			}
+		}
+		return true;
+	}
 }