Index: src/wp-admin/includes/class-wp-upgrader.php
===================================================================
--- src/wp-admin/includes/class-wp-upgrader.php	(revision 25651)
+++ src/wp-admin/includes/class-wp-upgrader.php	(working copy)
@@ -1254,11 +1254,11 @@
 		// Pre-cache the checksums for the versions we care about
 		get_core_checksums( array( $wp_version, $current->version ) );
 
-		$no_partial = false;
+		$partial = true;
 		if ( $parsed_args['do_rollback'] )
-			$no_partial = true;
+			$partial = false;
 		elseif ( $parsed_args['pre_check_md5'] && ! $this->check_files() )
-			$no_partial = true;
+			$partial = false;
 
 		// If partial update is returned from the API, use that, unless we're doing a reinstall.
 		// If we cross the new_bundled version number, then use the new_bundled zip.
@@ -1266,7 +1266,7 @@
 		// If the API returns a no_content zip, go with it. Finally, default to the full zip.
 		if ( $parsed_args['do_rollback'] && $current->packages->rollback )
 			$to_download = 'rollback';
-		elseif ( $current->packages->partial && 'reinstall' != $current->response && $wp_version == $current->partial_version && ! $no_partial )
+		elseif ( $current->packages->partial && 'reinstall' != $current->response && $wp_version == $current->partial_version && $partial )
 			$to_download = 'partial';
 		elseif ( $current->packages->new_bundled && version_compare( $wp_version, $current->new_bundled, '<' )
 			&& ( ! defined( 'CORE_UPGRADE_SKIP_NEW_BUNDLED' ) || ! CORE_UPGRADE_SKIP_NEW_BUNDLED ) )
@@ -1640,7 +1640,7 @@
 						$item->language
 					);
 				}
-				
+
 				break;
 		}
 
@@ -1688,10 +1688,10 @@
 			return;
 
 		// Don't automatically run these thins, as we'll handle it ourselves
-		remove_action( 'upgrader_process_complete', array( 'Language_Pack_Upgrader', 'async_upgrade' ), 20, 3 ); 
-		remove_action( 'upgrader_process_complete', 'wp_version_check' ); 
-		remove_action( 'upgrader_process_complete', 'wp_update_plugins' ); 
-		remove_action( 'upgrader_process_complete', 'wp_update_themes' ); 
+		remove_action( 'upgrader_process_complete', array( 'Language_Pack_Upgrader', 'async_upgrade' ), 20, 3 );
+		remove_action( 'upgrader_process_complete', 'wp_version_check' );
+		remove_action( 'upgrader_process_complete', 'wp_update_plugins' );
+		remove_action( 'upgrader_process_complete', 'wp_update_themes' );
 
 		// Next, Plugins
 		wp_update_plugins(); // Check for Plugin updates