diff -r c7c34916027a -r 177826044cd9 wp/wp-includes/class-wp-paused-extensions-storage.php
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/wp/wp-includes/class-wp-paused-extensions-storage.php	Mon Oct 14 18:28:13 2019 +0200
@@ -0,0 +1,223 @@
+<?php
+/**
+ * Error Protection API: WP_Paused_Extensions_Storage class
+ *
+ * @package WordPress
+ * @since   5.2.0
+ */
+
+/**
+ * Core class used for storing paused extensions.
+ *
+ * @since 5.2.0
+ */
+class WP_Paused_Extensions_Storage {
+
+	/**
+	 * Type of extension. Used to key extension storage.
+	 *
+	 * @since 5.2.0
+	 * @var string
+	 */
+	protected $type;
+
+	/**
+	 * Constructor.
+	 *
+	 * @since 5.2.0
+	 *
+	 * @param string $extension_type Extension type. Either 'plugin' or 'theme'.
+	 */
+	public function __construct( $extension_type ) {
+		$this->type = $extension_type;
+	}
+
+	/**
+	 * Records an extension error.
+	 *
+	 * Only one error is stored per extension, with subsequent errors for the same extension overriding the
+	 * previously stored error.
+	 *
+	 * @since 5.2.0
+	 *
+	 * @param string $extension Plugin or theme directory name.
+	 * @param array  $error     {
+	 *     Error that was triggered.
+	 *
+	 *     @type string $type    The error type.
+	 *     @type string $file    The name of the file in which the error occurred.
+	 *     @type string $line    The line number in which the error occurred.
+	 *     @type string $message The error message.
+	 * }
+	 * @return bool True on success, false on failure.
+	 */
+	public function set( $extension, $error ) {
+		if ( ! $this->is_api_loaded() ) {
+			return false;
+		}
+
+		$option_name = $this->get_option_name();
+
+		if ( ! $option_name ) {
+			return false;
+		}
+
+		$paused_extensions = (array) get_option( $option_name, array() );
+
+		// Do not update if the error is already stored.
+		if ( isset( $paused_extensions[ $this->type ][ $extension ] ) && $paused_extensions[ $this->type ][ $extension ] === $error ) {
+			return true;
+		}
+
+		$paused_extensions[ $this->type ][ $extension ] = $error;
+
+		return update_option( $option_name, $paused_extensions );
+	}
+
+	/**
+	 * Forgets a previously recorded extension error.
+	 *
+	 * @since 5.2.0
+	 *
+	 * @param string $extension Plugin or theme directory name.
+	 *
+	 * @return bool True on success, false on failure.
+	 */
+	public function delete( $extension ) {
+		if ( ! $this->is_api_loaded() ) {
+			return false;
+		}
+
+		$option_name = $this->get_option_name();
+
+		if ( ! $option_name ) {
+			return false;
+		}
+
+		$paused_extensions = (array) get_option( $option_name, array() );
+
+		// Do not delete if no error is stored.
+		if ( ! isset( $paused_extensions[ $this->type ][ $extension ] ) ) {
+			return true;
+		}
+
+		unset( $paused_extensions[ $this->type ][ $extension ] );
+
+		if ( empty( $paused_extensions[ $this->type ] ) ) {
+			unset( $paused_extensions[ $this->type ] );
+		}
+
+		// Clean up the entire option if we're removing the only error.
+		if ( ! $paused_extensions ) {
+			return delete_option( $option_name );
+		}
+
+		return update_option( $option_name, $paused_extensions );
+	}
+
+	/**
+	 * Gets the error for an extension, if paused.
+	 *
+	 * @since 5.2.0
+	 *
+	 * @param string $extension Plugin or theme directory name.
+	 *
+	 * @return array|null Error that is stored, or null if the extension is not paused.
+	 */
+	public function get( $extension ) {
+		if ( ! $this->is_api_loaded() ) {
+			return null;
+		}
+
+		$paused_extensions = $this->get_all();
+
+		if ( ! isset( $paused_extensions[ $extension ] ) ) {
+			return null;
+		}
+
+		return $paused_extensions[ $extension ];
+	}
+
+	/**
+	 * Gets the paused extensions with their errors.
+	 *
+	 * @since 5.2.0
+	 *
+	 * @return array Associative array of extension slugs to the error recorded.
+	 */
+	public function get_all() {
+		if ( ! $this->is_api_loaded() ) {
+			return array();
+		}
+
+		$option_name = $this->get_option_name();
+
+		if ( ! $option_name ) {
+			return array();
+		}
+
+		$paused_extensions = (array) get_option( $option_name, array() );
+
+		return isset( $paused_extensions[ $this->type ] ) ? $paused_extensions[ $this->type ] : array();
+	}
+
+	/**
+	 * Remove all paused extensions.
+	 *
+	 * @since 5.2.0
+	 *
+	 * @return bool
+	 */
+	public function delete_all() {
+		if ( ! $this->is_api_loaded() ) {
+			return false;
+		}
+
+		$option_name = $this->get_option_name();
+
+		if ( ! $option_name ) {
+			return false;
+		}
+
+		$paused_extensions = (array) get_option( $option_name, array() );
+
+		unset( $paused_extensions[ $this->type ] );
+
+		if ( ! $paused_extensions ) {
+			return delete_option( $option_name );
+		}
+
+		return update_option( $option_name, $paused_extensions );
+	}
+
+	/**
+	 * Checks whether the underlying API to store paused extensions is loaded.
+	 *
+	 * @since 5.2.0
+	 *
+	 * @return bool True if the API is loaded, false otherwise.
+	 */
+	protected function is_api_loaded() {
+		return function_exists( 'get_option' );
+	}
+
+	/**
+	 * Get the option name for storing paused extensions.
+	 *
+	 * @since 5.2.0
+	 *
+	 * @return string
+	 */
+	protected function get_option_name() {
+		if ( ! wp_recovery_mode()->is_active() ) {
+			return '';
+		}
+
+		$session_id = wp_recovery_mode()->get_session_id();
+		if ( empty( $session_id ) ) {
+			return '';
+		}
+
+		return "{$session_id}_paused_extensions";
+	}
+}