Ticket #30921: 30921.2.diff

src/wp-admin/includes/class-wp-upgrader.php

@@ -120 +120 @@
                 $this->strings['fs_unavailable'] = __('Could not access filesystem.');
                 $this->strings['fs_error'] = __('Filesystem error.');
                 $this->strings['fs_no_root_dir'] = __('Unable to locate WordPress Root directory.');
                 $this->strings['fs_no_content_dir'] = __('Unable to locate WordPress Content directory (wp-content).');
                 $this->strings['fs_no_plugins_dir'] = __('Unable to locate WordPress Plugin directory.');
                 $this->strings['fs_no_themes_dir'] = __('Unable to locate WordPress Theme directory.');
                 /* translators: %s: directory name */
                 $this->strings['fs_no_folder'] = __('Unable to locate needed folder (%s).');
 
                 $this->strings['download_failed'] = __('Download failed.');
                 $this->strings['installing_package'] = __('Installing the latest version…');
                 $this->strings['no_files'] = __('The package contains no files.');
                 $this->strings['folder_exists'] = __('Destination folder already exists.');
                 $this->strings['mkdir_failed'] = __('Could not create directory.');
                 $this->strings['incompatible_archive'] = __('The package could not be installed.');
+                $this->strings['files_not_writable'] = __( 'The update cannot be installed because we will be unable to copy some files. This is usually due to inconsistent file permissions.' );
 
                 $this->strings['maintenance_start'] = __('Enabling Maintenance mode…');
                 $this->strings['maintenance_end'] = __('Disabling Maintenance mode…');
         }
 
         /**
          * Connect to the filesystem.
          *
          * @since 2.8.0
          *
          * @global WP_Filesystem_Base $wp_filesystem Subclass
          *
          * @param array $directories                  Optional. A list of directories. If any of these do
          *                                            not exist, a {@see WP_Error} object will be returned.
          *                                            Default empty array.
@@ -281 +282 @@
                 if ( $delete_package )
                         unlink($package);
 
                 if ( is_wp_error($result) ) {
                         $wp_filesystem->delete($working_dir, true);
                         if ( 'incompatible_archive' == $result->get_error_code() ) {
                                 return new WP_Error( 'incompatible_archive', $this->strings['incompatible_archive'], $result->get_error_data() );
                         }
                         return $result;
                 }
 
                 return $working_dir;
         }
 
         /**
+         * Clears the directory where this item is going to be installed into.
+         *
+         * @since 4.3.0
+         *
+         * @global WP_Filesystem_Base $wp_filesystem Subclass
+         *
+         * @param string $remote_destination The location on the remote filesystem to be cleared
+         *
+         * @return bool|WP_Error true upon success, {@see WP_Error} on failure.
+         */
+        function clear_destination( $remote_destination ) {
+                global $wp_filesystem;
+
+                if ( ! $wp_filesystem->exists( $remote_destination ) ) {
+                        return true;
+                }
+
+                // Check all files are writable before attempting to clear the destination
+                $unwritable_files = array();
+
+                $_files = $wp_filesystem->dirlist( $remote_destination, true, true );
+                // Flatten the resulting array, iterate using each as we append to the array during iteration
+                while ( $f = each( $_files ) ) {
+                        $file = $f['value'];
+                        $name = $f['key'];
+
+                        if ( ! isset( $file['files'] ) ) {
+                                continue;
+                        }
+
+                        foreach ( $file['files'] as $filename => $details ) {
+                                $_files[ $name . '/' . $filename ] = $details;
+                        }
+                }
+
+                // Check writability
+                foreach ( $_files as $filename => $file_details ) {
+                        if ( ! $wp_filesystem->is_writable( $remote_destination . $filename ) ) {
+                                // Attempt to alter permissions to allow writes and try again
+                                $wp_filesystem->chmod( $remote_destination . $filename, ( 'd' == $file_details['type'] ? FS_CHMOD_DIR : FS_CHMOD_FILE ) );
+                                if ( ! $wp_filesystem->is_writable( $remote_destination . $filename ) ) {
+                                        $unwritable_files[] = $filename;
+                                }
+                        }
+                }
+
+                if ( ! empty( $unwritable_files ) ) {
+                        return new WP_Error( 'files_not_writable', $this->strings['files_not_writable'], implode( ', ', $unwritable_files ) );
+                }
+
+                if ( ! $wp_filesystem->delete( $remote_destination, true ) ) {
+                        return new WP_Error( 'remove_old_failed', $this->strings['remove_old_failed'] );
+                }
+
+                return true;
+        }
+
+        /**
          * Install a package.
          *
          * Copies the contents of a package form a source directory, and installs them in
          * a destination directory. Optionally removes the source. It can also optionally
          * clear out the destination folder if it already exists.
          *
          * @since 2.8.0
          *
          * @global WP_Filesystem_Base $wp_filesystem Subclass
          * @global array              $wp_theme_directories
          *
          * @param array|string $args {
          *     Optional. Array or string of arguments for installing a package. Default empty array.
          *
          *     @type string $source                      Required path to the package source. Default empty.
@@ -405 +464 @@
                  * destination directory (WP_PLUGIN_DIR / wp-content/themes) intending
                  * to copy the directory into the directory, whilst they pass the source
                  * as the actual files to copy.
                  */
                 $protected_directories = array( ABSPATH, WP_CONTENT_DIR, WP_PLUGIN_DIR, WP_CONTENT_DIR . '/themes' );
 
                 if ( is_array( $wp_theme_directories ) ) {
                         $protected_directories = array_merge( $protected_directories, $wp_theme_directories );
                 }
                 if ( in_array( $destination, $protected_directories ) ) {
                         $remote_destination = trailingslashit( $remote_destination ) . trailingslashit( basename( $source ) );
                         $destination = trailingslashit( $destination ) . trailingslashit( basename( $source ) );
                 }
 
                 if ( $clear_destination ) {
-                        //We're going to clear the destination if there's something there
+                        // We're going to clear the destination if there's something there
                         $this->skin->feedback('remove_old');
-                        $removed = true;
-                        if ( $wp_filesystem->exists( $remote_destination ) ) {
-                                $removed = $wp_filesystem->delete( $remote_destination, true );
-                        }
+
+                        $removed = $this->clear_destination( $remote_destination );
 
                         /**
                          * Filter whether the upgrader cleared the destination.
                          *
                          * @since 2.8.0
                          *
-                         * @param bool   $removed            Whether the destination was cleared.
+                         * @param mixed  $removed            Whether the destination was cleared. true on success, WP_Error on failure
                          * @param string $local_destination  The local package destination.
                          * @param string $remote_destination The remote package destination.
                          * @param array  $hook_extra         Extra arguments passed to hooked filters.
                          */
                         $removed = apply_filters( 'upgrader_clear_destination', $removed, $local_destination, $remote_destination, $args['hook_extra'] );
 
-                        if ( is_wp_error($removed) ) {
+                        if ( is_wp_error( $removed ) ) {
                                 return $removed;
-                        } elseif ( ! $removed ) {
-                                return new WP_Error('remove_old_failed', $this->strings['remove_old_failed']);
                         }
                 } elseif ( $args['abort_if_destination_exists'] && $wp_filesystem->exists($remote_destination) ) {
                         //If we're not clearing the destination folder and something exists there already, Bail.
                         //But first check to see if there are actually any files in the folder.
                         $_files = $wp_filesystem->dirlist($remote_destination);
                         if ( ! empty($_files) ) {
                                 $wp_filesystem->delete($remote_source, true); //Clear out the source files.
                                 return new WP_Error('folder_exists', $this->strings['folder_exists'], $remote_destination );
                         }
                 }
 
                 //Create destination if needed
                 if ( ! $wp_filesystem->exists( $remote_destination ) ) {
                         if ( ! $wp_filesystem->mkdir( $remote_destination, FS_CHMOD_DIR ) ) {
                                 return new WP_Error( 'mkdir_failed_destination', $this->strings['mkdir_failed'], $remote_destination );