Ticket #25860: 25860.diff

src/wp-admin/includes/update-core.php

@@ -748 +748 @@
         apply_filters( 'update_feedback', __( 'Preparing to install the latest version…' ) );
 
         // Don't copy wp-content, we'll deal with that below
-        $skip = array( 'wp-content' );
+        // We also copy version.php last so failed updates report their old version
+        $skip = array( 'wp-content', 'wp-includes/version.php' );
         $check_is_writable = array();
 
         // Check to see which files don't really need updating - only available for 3.7 and higher
@@ -810 +811 @@
         if ( is_wp_error( $result ) )
                 $result = new WP_Error( $result->get_error_code(), $result->get_error_message(), substr( $result->get_error_data(), strlen( $to ) ) );
 
+        // Since we know the core files have copied over, we can now copy the version file
+        if ( ! $wp_filesystem->copy( $from . $distro . 'wp-includes/version.php', $to . 'wp-includes/version.php' ) ) {
+                 $wp_filesystem->delete( $from, true );
+                 return new WP_Error( 'copy_failed_for_version_file', __( 'The update cannot be installed because we will be unable to copy some files. This is usually due to inconsistent file permissions.' ), 'wp-includes/version.php' );
+        }
+        $wp_filesystem->chmod( $to . 'wp-includes/version.php', FS_CHMOD_FILE );
+
         // Check to make sure everything copied correctly, ignoring the contents of wp-content
         $skip = array( 'wp-content' );
         $failed = array();