Merge branch 'archwiki'

Conflicts:
	extensions/FluxBBAuthPlugin.php
	extensions/SyntaxHighlight_GeSHi/README
	extensions/SyntaxHighlight_GeSHi/SyntaxHighlight_GeSHi.class.php
	extensions/SyntaxHighlight_GeSHi/SyntaxHighlight_GeSHi.i18n.php
	extensions/SyntaxHighlight_GeSHi/SyntaxHighlight_GeSHi.php
	extensions/SyntaxHighlight_GeSHi/geshi/docs/CHANGES
	extensions/SyntaxHighlight_GeSHi/geshi/docs/THANKS
	extensions/SyntaxHighlight_GeSHi/geshi/docs/TODO
	extensions/SyntaxHighlight_GeSHi/geshi/docs/api/media/images/AbstractClass.png
	extensions/SyntaxHighlight_GeSHi/geshi/docs/api/media/images/AbstractClass_logo.png
	extensions/SyntaxHighlight_GeSHi/geshi/docs/api/media/images/AbstractMethod.png
	extensions/SyntaxHighlight_GeSHi/geshi/docs/api/media/images/AbstractPrivateClass.png
	extensions/SyntaxHighlight_GeSHi/geshi/docs/api/media/images/AbstractPrivateClass_logo.png
	extensions/SyntaxHighlight_GeSHi/geshi/docs/api/media/images/AbstractPrivateMethod.png
	extensions/SyntaxHighlight_GeSHi/geshi/docs/api/media/images/Class.png
	extensions/SyntaxHighlight_GeSHi/geshi/docs/api/media/images/Class_logo.png
	extensions/SyntaxHighlight_GeSHi/geshi/docs/api/media/images/Constant.png
	extensions/SyntaxHighlight_GeSHi/geshi/docs/api/media/images/Constructor.png
	extensions/SyntaxHighlight_GeSHi/geshi/docs/api/media/images/Destructor.png
	extensions/SyntaxHighlight_GeSHi/geshi/docs/api/media/images/Function.png
	extensions/SyntaxHighlight_GeSHi/geshi/docs/api/media/images/Global.png
	extensions/SyntaxHighlight_GeSHi/geshi/docs/api/media/images/I.png
	extensions/SyntaxHighlight_GeSHi/geshi/docs/api/media/images/Index.png
	extensions/SyntaxHighlight_GeSHi/geshi/docs/api/media/images/Interface.png
	extensions/SyntaxHighlight_GeSHi/geshi/docs/api/media/images/Interface_logo.png
	extensions/SyntaxHighlight_GeSHi/geshi/docs/api/media/images/L.png
	extensions/SyntaxHighlight_GeSHi/geshi/docs/api/media/images/Lminus.png
	extensions/SyntaxHighlight_GeSHi/geshi/docs/api/media/images/Lplus.png
	extensions/SyntaxHighlight_GeSHi/geshi/docs/api/media/images/Method.png
	extensions/SyntaxHighlight_GeSHi/geshi/docs/api/media/images/Page.png
	extensions/SyntaxHighlight_GeSHi/geshi/docs/api/media/images/Page_logo.png
	extensions/SyntaxHighlight_GeSHi/geshi/docs/api/media/images/PrivateClass.png
	extensions/SyntaxHighlight_GeSHi/geshi/docs/api/media/images/PrivateClass_logo.png
	extensions/SyntaxHighlight_GeSHi/geshi/docs/api/media/images/PrivateMethod.png
	extensions/SyntaxHighlight_GeSHi/geshi/docs/api/media/images/PrivateVariable.png
	extensions/SyntaxHighlight_GeSHi/geshi/docs/api/media/images/StaticMethod.png
	extensions/SyntaxHighlight_GeSHi/geshi/docs/api/media/images/StaticVariable.png
	extensions/SyntaxHighlight_GeSHi/geshi/docs/api/media/images/T.png
	extensions/SyntaxHighlight_GeSHi/geshi/docs/api/media/images/Tminus.png
	extensions/SyntaxHighlight_GeSHi/geshi/docs/api/media/images/Tplus.png
	extensions/SyntaxHighlight_GeSHi/geshi/docs/api/media/images/Variable.png
	extensions/SyntaxHighlight_GeSHi/geshi/docs/api/media/images/blank.png
	extensions/SyntaxHighlight_GeSHi/geshi/docs/api/media/images/class_folder.png
	extensions/SyntaxHighlight_GeSHi/geshi/docs/api/media/images/file.png
	extensions/SyntaxHighlight_GeSHi/geshi/docs/api/media/images/folder.png
	extensions/SyntaxHighlight_GeSHi/geshi/docs/api/media/images/function_folder.png
	extensions/SyntaxHighlight_GeSHi/geshi/docs/api/media/images/next_button.png
	extensions/SyntaxHighlight_GeSHi/geshi/docs/api/media/images/next_button_disabled.png
	extensions/SyntaxHighlight_GeSHi/geshi/docs/api/media/images/package.png
	extensions/SyntaxHighlight_GeSHi/geshi/docs/api/media/images/package_folder.png
	extensions/SyntaxHighlight_GeSHi/geshi/docs/api/media/images/previous_button.png
	extensions/SyntaxHighlight_GeSHi/geshi/docs/api/media/images/previous_button_disabled.png
	extensions/SyntaxHighlight_GeSHi/geshi/docs/api/media/images/private_class_logo.png
	extensions/SyntaxHighlight_GeSHi/geshi/docs/api/media/images/tutorial.png
	extensions/SyntaxHighlight_GeSHi/geshi/docs/api/media/images/tutorial_folder.png
	extensions/SyntaxHighlight_GeSHi/geshi/docs/api/media/images/up_button.png
	extensions/SyntaxHighlight_GeSHi/geshi/docs/geshi-doc.html
	extensions/SyntaxHighlight_GeSHi/geshi/docs/geshi-doc.txt
	extensions/SyntaxHighlight_GeSHi/geshi/geshi.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/4cs.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/6502acme.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/6502kickass.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/6502tasm.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/68000devpac.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/abap.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/actionscript.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/actionscript3.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/ada.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/algol68.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/apache.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/applescript.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/apt_sources.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/asm.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/asp.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/autoconf.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/autohotkey.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/autoit.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/avisynth.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/awk.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/bascomavr.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/bash.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/basic4gl.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/bf.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/bibtex.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/blitzbasic.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/bnf.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/boo.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/c.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/c_loadrunner.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/c_mac.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/caddcl.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/cadlisp.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/cfdg.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/cfm.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/chaiscript.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/cil.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/clojure.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/cmake.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/cobol.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/coffeescript.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/cpp-qt.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/cpp.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/csharp.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/css.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/cuesheet.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/d.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/dcs.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/delphi.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/diff.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/div.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/dos.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/dot.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/e.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/ecmascript.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/eiffel.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/email.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/epc.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/erlang.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/euphoria.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/f1.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/falcon.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/fo.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/fortran.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/freebasic.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/fsharp.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/gambas.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/gdb.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/genero.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/genie.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/gettext.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/glsl.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/gml.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/gnuplot.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/go.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/groovy.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/gwbasic.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/haskell.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/hicest.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/hq9plus.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/html4strict.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/html5.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/icon.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/idl.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/ini.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/inno.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/intercal.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/io.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/j.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/java.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/java5.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/javascript.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/jquery.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/kixtart.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/klonec.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/klonecpp.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/latex.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/lb.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/lisp.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/llvm.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/locobasic.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/logtalk.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/lolcode.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/lotusformulas.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/lotusscript.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/lscript.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/lsl2.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/lua.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/m68k.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/magiksf.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/make.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/mapbasic.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/matlab.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/mirc.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/mmix.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/modula2.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/modula3.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/mpasm.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/mxml.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/mysql.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/newlisp.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/nsis.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/oberon2.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/objc.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/objeck.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/ocaml-brief.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/ocaml.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/oobas.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/oracle11.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/oracle8.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/oxygene.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/oz.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/pascal.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/pcre.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/per.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/perl.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/perl6.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/pf.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/php-brief.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/php.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/pic16.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/pike.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/pixelbender.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/pli.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/plsql.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/postgresql.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/povray.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/powerbuilder.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/powershell.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/proftpd.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/progress.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/prolog.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/properties.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/providex.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/purebasic.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/pycon.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/python.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/q.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/qbasic.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/rails.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/rebol.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/reg.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/robots.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/rpmspec.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/rsplus.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/ruby.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/sas.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/scala.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/scheme.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/scilab.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/sdlbasic.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/smalltalk.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/smarty.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/sql.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/systemverilog.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/tcl.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/teraterm.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/text.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/thinbasic.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/tsql.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/typoscript.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/unicon.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/uscript.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/vala.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/vb.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/vbnet.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/verilog.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/vhdl.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/vim.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/visualfoxpro.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/visualprolog.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/whitespace.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/whois.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/winbatch.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/xbasic.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/xml.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/xorg_conf.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/xpp.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/yaml.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/z80.php
	extensions/SyntaxHighlight_GeSHi/geshi/geshi/zxbasic.php

1 files changed, 393 insertions, 102 deletions

diff --git a/includes/installer/DatabaseUpdater.php b/includes/installer/DatabaseUpdater.php
index ff0a99e9..267b6c5a 100644
--- a/includes/installer/DatabaseUpdater.php
+++ b/includes/installer/DatabaseUpdater.php
@@ -21,7 +21,7 @@
  * @ingroup Deployment
  */
 
-require_once( __DIR__ . '/../../maintenance/Maintenance.php' );
+require_once __DIR__ . '/../../maintenance/Maintenance.php';
 
 /**
  * Class for handling database updates. Roughly based off of updaters.inc, with
@@ -40,6 +40,13 @@ abstract class DatabaseUpdater {
 	protected $updates = array();
 
 	/**
+	 * Array of updates that were skipped
+	 *
+	 * @var array
+	 */
+	protected $updatesSkipped = array();
+
+	/**
 	 * List of extension-provided database updates
 	 * @var array
 	 */
@@ -54,19 +61,38 @@ abstract class DatabaseUpdater {
 
 	protected $shared = false;
 
+	/**
+	 * Scripts to run after database update
+	 * Should be a subclass of LoggedUpdateMaintenance
+	 */
 	protected $postDatabaseUpdateMaintenance = array(
 		'DeleteDefaultMessages',
 		'PopulateRevisionLength',
 		'PopulateRevisionSha1',
 		'PopulateImageSha1',
 		'FixExtLinksProtocolRelative',
+		'PopulateFilearchiveSha1',
 	);
 
 	/**
+	 * File handle for SQL output.
+	 *
+	 * @var Filehandle
+	 */
+	protected $fileHandle = null;
+
+	/**
+	 * Flag specifying whether or not to skip schema (e.g. SQL-only) updates.
+	 *
+	 * @var bool
+	 */
+	protected $skipSchema = false;
+
+	/**
 	 * Constructor
 	 *
 	 * @param $db DatabaseBase object to perform updates on
-	 * @param $shared bool Whether to perform updates on shared tables
+	 * @param bool $shared Whether to perform updates on shared tables
 	 * @param $maintenance Maintenance Maintenance object which created us
 	 */
 	protected function __construct( DatabaseBase &$db, $shared, Maintenance $maintenance = null ) {
@@ -75,6 +101,7 @@ abstract class DatabaseUpdater {
 		$this->shared = $shared;
 		if ( $maintenance ) {
 			$this->maintenance = $maintenance;
+			$this->fileHandle = $maintenance->fileHandle;
 		} else {
 			$this->maintenance = new FakeMaintenance;
 		}
@@ -103,7 +130,8 @@ abstract class DatabaseUpdater {
 	}
 
 	/**
-	 * Loads LocalSettings.php, if needed, and initialises everything needed for LoadExtensionSchemaUpdates hook
+	 * Loads LocalSettings.php, if needed, and initialises everything needed for
+	 * LoadExtensionSchemaUpdates hook.
 	 */
 	private function loadExtensions() {
 		if ( !defined( 'MEDIAWIKI_INSTALL' ) ) {
@@ -130,8 +158,9 @@ abstract class DatabaseUpdater {
 	 */
 	public static function newForDB( &$db, $shared = false, $maintenance = null ) {
 		$type = $db->getType();
-		if( in_array( $type, Installer::getDBTypes() ) ) {
+		if ( in_array( $type, Installer::getDBTypes() ) ) {
 			$class = ucfirst( $type ) . 'Updater';
+
 			return new $class( $db, $shared, $maintenance );
 		} else {
 			throw new MWException( __METHOD__ . ' called for unsupported $wgDBtype' );
@@ -150,14 +179,14 @@ abstract class DatabaseUpdater {
 	/**
 	 * Output some text. If we're running from web, escape the text first.
 	 *
-	 * @param $str String: Text to output
+	 * @param string $str Text to output
 	 */
 	public function output( $str ) {
 		if ( $this->maintenance->isQuiet() ) {
 			return;
 		}
 		global $wgCommandLineMode;
-		if( !$wgCommandLineMode ) {
+		if ( !$wgCommandLineMode ) {
 			$str = htmlspecialchars( $str );
 		}
 		echo $str;
@@ -170,14 +199,14 @@ abstract class DatabaseUpdater {
 	 *
 	 * @since 1.17
 	 *
-	 * @param $update Array: the update to run. Format is the following:
+	 * @param array $update the update to run. Format is the following:
 	 *                first item is the callback function, it also can be a
 	 *                simple string with the name of a function in this class,
 	 *                following elements are parameters to the function.
 	 *                Note that callback functions will receive this object as
 	 *                first parameter.
 	 */
-	public function addExtensionUpdate( Array $update ) {
+	public function addExtensionUpdate( array $update ) {
 		$this->extensionUpdates[] = $update;
 	}
 
@@ -187,8 +216,8 @@ abstract class DatabaseUpdater {
 	 *
 	 * @since 1.18
 	 *
-	 * @param $tableName String Name of table to create
-	 * @param $sqlPath String Full path to the schema file
+	 * @param string $tableName Name of table to create
+	 * @param string $sqlPath Full path to the schema file
 	 */
 	public function addExtensionTable( $tableName, $sqlPath ) {
 		$this->extensionUpdates[] = array( 'addTable', $tableName, $sqlPath, true );
@@ -230,6 +259,19 @@ abstract class DatabaseUpdater {
 	}
 
 	/**
+	 * Drop an index from an extension table
+	 *
+	 * @since 1.21
+	 *
+	 * @param string $tableName The table name
+	 * @param string $indexName The index name
+	 * @param string $sqlPath The path to the SQL change path
+	 */
+	public function dropExtensionIndex( $tableName, $indexName, $sqlPath ) {
+		$this->extensionUpdates[] = array( 'dropIndex', $tableName, $indexName, $sqlPath, true );
+	}
+
+	/**
 	 *
 	 * @since 1.20
 	 *
@@ -241,6 +283,43 @@ abstract class DatabaseUpdater {
 	}
 
 	/**
+	 * Rename an index on an extension table
+	 *
+	 * @since 1.21
+	 *
+	 * @param string $tableName The table name
+	 * @param string $oldIndexName The old index name
+	 * @param string $newIndexName The new index name
+	 * @param $skipBothIndexExistWarning Boolean: Whether to warn if both the old
+	 * and the new indexes exist. [facultative; by default, false]
+	 * @param string $sqlPath The path to the SQL change path
+	 */
+	public function renameExtensionIndex( $tableName, $oldIndexName, $newIndexName,
+		$sqlPath, $skipBothIndexExistWarning = false
+	) {
+		$this->extensionUpdates[] = array(
+			'renameIndex',
+			$tableName,
+			$oldIndexName,
+			$newIndexName,
+			$skipBothIndexExistWarning,
+			$sqlPath,
+			true
+		);
+	}
+
+	/**
+	 * @since 1.21
+	 *
+	 * @param string $tableName The table name
+	 * @param string $fieldName The field to be modified
+	 * @param string $sqlPath The path to the SQL change path
+	 */
+	public function modifyExtensionField( $tableName, $fieldName, $sqlPath ) {
+		$this->extensionUpdates[] = array( 'modifyField', $tableName, $fieldName, $sqlPath, true );
+	}
+
+	/**
 	 *
 	 * @since 1.20
 	 *
@@ -254,9 +333,11 @@ abstract class DatabaseUpdater {
 	/**
 	 * Add a maintenance script to be run after the database updates are complete.
 	 *
+	 * Script should subclass LoggedUpdateMaintenance
+	 *
 	 * @since 1.19
 	 *
-	 * @param $class string Name of a Maintenance subclass
+	 * @param string $class Name of a Maintenance subclass
 	 */
 	public function addPostDatabaseUpdateMaintenance( $class ) {
 		$this->postDatabaseUpdateMaintenance[] = $class;
@@ -281,15 +362,35 @@ abstract class DatabaseUpdater {
 	}
 
 	/**
+	 * @since 1.21
+	 *
+	 * Writes the schema updates desired to a file for the DB Admin to run.
+	 */
+	private function writeSchemaUpdateFile( $schemaUpdate = array() ) {
+		$updates = $this->updatesSkipped;
+		$this->updatesSkipped = array();
+
+		foreach ( $updates as $funcList ) {
+			$func = $funcList[0];
+			$arg = $funcList[1];
+			$origParams = $funcList[2];
+			call_user_func_array( $func, $arg );
+			flush();
+			$this->updatesSkipped[] = $origParams;
+		}
+	}
+
+	/**
 	 * Do all the updates
 	 *
-	 * @param $what Array: what updates to perform
+	 * @param array $what what updates to perform
 	 */
-	public function doUpdates( $what = array( 'core', 'extensions', 'purge', 'stats' ) ) {
-		global $wgLocalisationCacheConf, $wgVersion;
+	public function doUpdates( $what = array( 'core', 'extensions', 'stats' ) ) {
+		global $wgVersion;
 
 		$this->db->begin( __METHOD__ );
 		$what = array_flip( $what );
+		$this->skipSchema = isset( $what['noschema'] ) || $this->fileHandle !== null;
 		if ( isset( $what['core'] ) ) {
 			$this->runUpdates( $this->getCoreUpdateList(), false );
 		}
@@ -298,41 +399,49 @@ abstract class DatabaseUpdater {
 			$this->runUpdates( $this->getExtensionUpdates(), true );
 		}
 
-		$this->setAppliedUpdates( $wgVersion, $this->updates );
-
 		if ( isset( $what['stats'] ) ) {
 			$this->checkStats();
 		}
 
-		if ( isset( $what['purge'] ) ) {
-			$this->purgeCache();
+		$this->setAppliedUpdates( $wgVersion, $this->updates );
 
-			if ( $wgLocalisationCacheConf['manualRecache'] ) {
-				$this->rebuildLocalisationCache();
-			}
+		if ( $this->fileHandle ) {
+			$this->skipSchema = false;
+			$this->writeSchemaUpdateFile();
+			$this->setAppliedUpdates( "$wgVersion-schema", $this->updatesSkipped );
 		}
+
 		$this->db->commit( __METHOD__ );
 	}
 
 	/**
 	 * Helper function for doUpdates()
 	 *
-	 * @param $updates Array of updates to run
+	 * @param array $updates of updates to run
 	 * @param $passSelf Boolean: whether to pass this object we calling external
 	 *                  functions
 	 */
 	private function runUpdates( array $updates, $passSelf ) {
+		$updatesDone = array();
+		$updatesSkipped = array();
 		foreach ( $updates as $params ) {
+			$origParams = $params;
 			$func = array_shift( $params );
-			if( !is_array( $func ) && method_exists( $this, $func ) ) {
+			if ( !is_array( $func ) && method_exists( $this, $func ) ) {
 				$func = array( $this, $func );
 			} elseif ( $passSelf ) {
 				array_unshift( $params, $this );
 			}
-			call_user_func_array( $func, $params );
+			$ret = call_user_func_array( $func, $params );
 			flush();
+			if ( $ret !== false ) {
+				$updatesDone[] = $origParams;
+			} else {
+				$updatesSkipped[] = array( $func, $params, $origParams );
+			}
 		}
-		$this->updates = array_merge( $this->updates, $updates );
+		$this->updatesSkipped = array_merge( $this->updatesSkipped, $updatesSkipped );
+		$this->updates = array_merge( $this->updates, $updatesDone );
 	}
 
 	/**
@@ -341,13 +450,13 @@ abstract class DatabaseUpdater {
 	 */
 	protected function setAppliedUpdates( $version, $updates = array() ) {
 		$this->db->clearFlag( DBO_DDLMODE );
-		if( !$this->canUseNewUpdatelog() ) {
+		if ( !$this->canUseNewUpdatelog() ) {
 			return;
 		}
 		$key = "updatelist-$version-" . time();
 		$this->db->insert( 'updatelog',
 			array( 'ul_key' => $key, 'ul_value' => serialize( $updates ) ),
-			 __METHOD__ );
+			__METHOD__ );
 		$this->db->setFlag( DBO_DDLMODE );
 	}
 
@@ -355,7 +464,7 @@ abstract class DatabaseUpdater {
 	 * Helper function: check if the given key is present in the updatelog table.
 	 * Obviously, only use this for updates that occur after the updatelog table was
 	 * created!
-	 * @param $key String Name of the key to check for
+	 * @param string $key Name of the key to check for
 	 *
 	 * @return bool
 	 */
@@ -366,6 +475,7 @@ abstract class DatabaseUpdater {
 			array( 'ul_key' => $key ),
 			__METHOD__
 		);
+
 		return (bool)$row;
 	}
 
@@ -373,13 +483,13 @@ abstract class DatabaseUpdater {
 	 * Helper function: Add a key to the updatelog table
 	 * Obviously, only use this for updates that occur after the updatelog table was
 	 * created!
-	 * @param $key String Name of key to insert
-	 * @param $val String [optional] value to insert along with the key
+	 * @param string $key Name of key to insert
+	 * @param string $val [optional] value to insert along with the key
 	 */
 	public function insertUpdateRow( $key, $val = null ) {
 		$this->db->clearFlag( DBO_DDLMODE );
 		$values = array( 'ul_key' => $key );
-		if( $val && $this->canUseNewUpdatelog() ) {
+		if ( $val && $this->canUseNewUpdatelog() ) {
 			$values['ul_value'] = $val;
 		}
 		$this->db->insert( 'updatelog', $values, __METHOD__, 'IGNORE' );
@@ -400,6 +510,26 @@ abstract class DatabaseUpdater {
 	}
 
 	/**
+	 * Returns whether updates should be executed on the database table $name.
+	 * Updates will be prevented if the table is a shared table and it is not
+	 * specified to run updates on shared tables.
+	 *
+	 * @param string $name table name
+	 * @return bool
+	 */
+	protected function doTable( $name ) {
+		global $wgSharedDB, $wgSharedTables;
+
+		// Don't bother to check $wgSharedTables if there isn't a shared database
+		// or the user actually also wants to do updates on the shared database.
+		if ( $wgSharedDB === null || $this->shared ) {
+			return true;
+		}
+
+		return !in_array( $name, $wgSharedTables );
+	}
+
+	/**
 	 * Before 1.17, we used to handle updates via stuff like
 	 * $wgExtNewTables/Fields/Indexes. This is nasty :) We refactored a lot
 	 * of this in 1.17 but we want to remain back-compatible for a while. So
@@ -409,11 +539,7 @@ abstract class DatabaseUpdater {
 	 */
 	protected function getOldGlobalUpdates() {
 		global $wgExtNewFields, $wgExtNewTables, $wgExtModifiedFields,
-			$wgExtNewIndexes, $wgSharedDB, $wgSharedTables;
-
-		$doUser = $this->shared ?
-			$wgSharedDB && in_array( 'user', $wgSharedTables ) :
-			!$wgSharedDB || !in_array( 'user', $wgSharedTables );
+			$wgExtNewIndexes;
 
 		$updates = array();
 
@@ -424,25 +550,23 @@ abstract class DatabaseUpdater {
 		}
 
 		foreach ( $wgExtNewFields as $fieldRecord ) {
-			if ( $fieldRecord[0] != 'user' || $doUser ) {
-				$updates[] = array(
-					'addField', $fieldRecord[0], $fieldRecord[1],
-						$fieldRecord[2], true
-				);
-			}
+			$updates[] = array(
+				'addField', $fieldRecord[0], $fieldRecord[1],
+				$fieldRecord[2], true
+			);
 		}
 
 		foreach ( $wgExtNewIndexes as $fieldRecord ) {
 			$updates[] = array(
 				'addIndex', $fieldRecord[0], $fieldRecord[1],
-					$fieldRecord[2], true
+				$fieldRecord[2], true
 			);
 		}
 
 		foreach ( $wgExtModifiedFields as $fieldRecord ) {
 			$updates[] = array(
 				'modifyField', $fieldRecord[0], $fieldRecord[1],
-					$fieldRecord[2], true
+				$fieldRecord[2], true
 			);
 		}
 
@@ -457,104 +581,242 @@ abstract class DatabaseUpdater {
 	 *
 	 * @return Array
 	 */
-	protected abstract function getCoreUpdateList();
+	abstract protected function getCoreUpdateList();
+
+	/**
+	 * Append an SQL fragment to the open file handle.
+	 *
+	 * @param string $filename File name to open
+	 */
+	public function copyFile( $filename ) {
+		$this->db->sourceFile( $filename, false, false, false,
+			array( $this, 'appendLine' )
+		);
+	}
+
+	/**
+	 * Append a line to the open filehandle.  The line is assumed to
+	 * be a complete SQL statement.
+	 *
+	 * This is used as a callback for for sourceLine().
+	 *
+	 * @param string $line text to append to the file
+	 * @return Boolean false to skip actually executing the file
+	 * @throws MWException
+	 */
+	public function appendLine( $line ) {
+		$line = rtrim( $line ) . ";\n";
+		if ( fwrite( $this->fileHandle, $line ) === false ) {
+			throw new MWException( "trouble writing file" );
+		}
+
+		return false;
+	}
 
 	/**
 	 * Applies a SQL patch
-	 * @param $path String Path to the patch file
+	 *
+	 * @param string $path Path to the patch file
 	 * @param $isFullPath Boolean Whether to treat $path as a relative or not
-	 * @param $msg String Description of the patch
+	 * @param string $msg Description of the patch
+	 * @return boolean false if patch is skipped.
 	 */
 	protected function applyPatch( $path, $isFullPath = false, $msg = null ) {
 		if ( $msg === null ) {
 			$msg = "Applying $path patch";
 		}
+		if ( $this->skipSchema ) {
+			$this->output( "...skipping schema change ($msg).\n" );
 
-		if ( !$isFullPath ) {
-			$path = $this->db->patchPath( $path );
+			return false;
 		}
 
 		$this->output( "$msg ..." );
-		$this->db->sourceFile( $path );
+
+		if ( !$isFullPath ) {
+			$path = $this->db->patchPath( $path );
+		}
+		if ( $this->fileHandle !== null ) {
+			$this->copyFile( $path );
+		} else {
+			$this->db->sourceFile( $path );
+		}
 		$this->output( "done.\n" );
+
+		return true;
 	}
 
 	/**
 	 * Add a new table to the database
-	 * @param $name String Name of the new table
-	 * @param $patch String Path to the patch file
+	 *
+	 * @param string $name Name of the new table
+	 * @param string $patch Path to the patch file
 	 * @param $fullpath Boolean Whether to treat $patch path as a relative or not
+	 * @return Boolean false if this was skipped because schema changes are skipped
 	 */
 	protected function addTable( $name, $patch, $fullpath = false ) {
+		if ( !$this->doTable( $name ) ) {
+			return true;
+		}
+
 		if ( $this->db->tableExists( $name, __METHOD__ ) ) {
 			$this->output( "...$name table already exists.\n" );
 		} else {
-			$this->applyPatch( $patch, $fullpath, "Creating $name table" );
+			return $this->applyPatch( $patch, $fullpath, "Creating $name table" );
 		}
+
+		return true;
 	}
 
 	/**
 	 * Add a new field to an existing table
-	 * @param $table String Name of the table to modify
-	 * @param $field String Name of the new field
-	 * @param $patch String Path to the patch file
+	 *
+	 * @param string $table Name of the table to modify
+	 * @param string $field Name of the new field
+	 * @param string $patch Path to the patch file
 	 * @param $fullpath Boolean Whether to treat $patch path as a relative or not
+	 * @return Boolean false if this was skipped because schema changes are skipped
 	 */
 	protected function addField( $table, $field, $patch, $fullpath = false ) {
+		if ( !$this->doTable( $table ) ) {
+			return true;
+		}
+
 		if ( !$this->db->tableExists( $table, __METHOD__ ) ) {
 			$this->output( "...$table table does not exist, skipping new field patch.\n" );
 		} elseif ( $this->db->fieldExists( $table, $field, __METHOD__ ) ) {
 			$this->output( "...have $field field in $table table.\n" );
 		} else {
-			$this->applyPatch( $patch, $fullpath, "Adding $field field to table $table" );
+			return $this->applyPatch( $patch, $fullpath, "Adding $field field to table $table" );
 		}
+
+		return true;
 	}
 
 	/**
 	 * Add a new index to an existing table
-	 * @param $table String Name of the table to modify
-	 * @param $index String Name of the new index
-	 * @param $patch String Path to the patch file
+	 *
+	 * @param string $table Name of the table to modify
+	 * @param string $index Name of the new index
+	 * @param string $patch Path to the patch file
 	 * @param $fullpath Boolean Whether to treat $patch path as a relative or not
+	 * @return Boolean false if this was skipped because schema changes are skipped
 	 */
 	protected function addIndex( $table, $index, $patch, $fullpath = false ) {
-		if ( $this->db->indexExists( $table, $index, __METHOD__ ) ) {
+		if ( !$this->doTable( $table ) ) {
+			return true;
+		}
+
+		if ( !$this->db->tableExists( $table, __METHOD__ ) ) {
+			$this->output( "...skipping: '$table' table doesn't exist yet.\n" );
+		} elseif ( $this->db->indexExists( $table, $index, __METHOD__ ) ) {
 			$this->output( "...index $index already set on $table table.\n" );
 		} else {
-			$this->applyPatch( $patch, $fullpath, "Adding index $index to table $table" );
+			return $this->applyPatch( $patch, $fullpath, "Adding index $index to table $table" );
 		}
+
+		return true;
 	}
 
 	/**
 	 * Drop a field from an existing table
 	 *
-	 * @param $table String Name of the table to modify
-	 * @param $field String Name of the old field
-	 * @param $patch String Path to the patch file
+	 * @param string $table Name of the table to modify
+	 * @param string $field Name of the old field
+	 * @param string $patch Path to the patch file
 	 * @param $fullpath Boolean Whether to treat $patch path as a relative or not
+	 * @return Boolean false if this was skipped because schema changes are skipped
 	 */
 	protected function dropField( $table, $field, $patch, $fullpath = false ) {
+		if ( !$this->doTable( $table ) ) {
+			return true;
+		}
+
 		if ( $this->db->fieldExists( $table, $field, __METHOD__ ) ) {
-			$this->applyPatch( $patch, $fullpath, "Table $table contains $field field. Dropping" );
+			return $this->applyPatch( $patch, $fullpath, "Table $table contains $field field. Dropping" );
 		} else {
 			$this->output( "...$table table does not contain $field field.\n" );
 		}
+
+		return true;
 	}
 
 	/**
 	 * Drop an index from an existing table
 	 *
-	 * @param $table String: Name of the table to modify
-	 * @param $index String: Name of the old index
-	 * @param $patch String: Path to the patch file
+	 * @param string $table Name of the table to modify
+	 * @param string $index Name of the index
+	 * @param string $patch Path to the patch file
 	 * @param $fullpath Boolean: Whether to treat $patch path as a relative or not
+	 * @return Boolean false if this was skipped because schema changes are skipped
 	 */
 	protected function dropIndex( $table, $index, $patch, $fullpath = false ) {
+		if ( !$this->doTable( $table ) ) {
+			return true;
+		}
+
 		if ( $this->db->indexExists( $table, $index, __METHOD__ ) ) {
-			$this->applyPatch( $patch, $fullpath, "Dropping $index index from table $table" );
+			return $this->applyPatch( $patch, $fullpath, "Dropping $index index from table $table" );
 		} else {
 			$this->output( "...$index key doesn't exist.\n" );
 		}
+
+		return true;
+	}
+
+	/**
+	 * Rename an index from an existing table
+	 *
+	 * @param string $table Name of the table to modify
+	 * @param string $oldIndex Old name of the index
+	 * @param string $newIndex New name of the index
+	 * @param $skipBothIndexExistWarning Boolean: Whether to warn if both the
+	 * old and the new indexes exist.
+	 * @param string $patch Path to the patch file
+	 * @param $fullpath Boolean: Whether to treat $patch path as a relative or not
+	 * @return Boolean false if this was skipped because schema changes are skipped
+	 */
+	protected function renameIndex( $table, $oldIndex, $newIndex,
+		$skipBothIndexExistWarning, $patch, $fullpath = false
+	) {
+		if ( !$this->doTable( $table ) ) {
+			return true;
+		}
+
+		// First requirement: the table must exist
+		if ( !$this->db->tableExists( $table, __METHOD__ ) ) {
+			$this->output( "...skipping: '$table' table doesn't exist yet.\n" );
+
+			return true;
+		}
+
+		// Second requirement: the new index must be missing
+		if ( $this->db->indexExists( $table, $newIndex, __METHOD__ ) ) {
+			$this->output( "...index $newIndex already set on $table table.\n" );
+			if ( !$skipBothIndexExistWarning &&
+				$this->db->indexExists( $table, $oldIndex, __METHOD__ )
+			) {
+				$this->output( "...WARNING: $oldIndex still exists, despite it has " .
+					"been renamed into $newIndex (which also exists).\n" .
+					"            $oldIndex should be manually removed if not needed anymore.\n" );
+			}
+
+			return true;
+		}
+
+		// Third requirement: the old index must exist
+		if ( !$this->db->indexExists( $table, $oldIndex, __METHOD__ ) ) {
+			$this->output( "...skipping: index $oldIndex doesn't exist.\n" );
+
+			return true;
+		}
+
+		// Requirements have been satisfied, patch can be applied
+		return $this->applyPatch(
+			$patch,
+			$fullpath,
+			"Renaming index $oldIndex into $newIndex to table $table"
+		);
 	}
 
 	/**
@@ -566,8 +828,13 @@ abstract class DatabaseUpdater {
 	 * @param $table string
 	 * @param $patch string|false
 	 * @param $fullpath bool
+	 * @return Boolean false if this was skipped because schema changes are skipped
 	 */
 	public function dropTable( $table, $patch = false, $fullpath = false ) {
+		if ( !$this->doTable( $table ) ) {
+			return true;
+		}
+
 		if ( $this->db->tableExists( $table, __METHOD__ ) ) {
 			$msg = "Dropping table $table";
 
@@ -575,46 +842,60 @@ abstract class DatabaseUpdater {
 				$this->output( "$msg ..." );
 				$this->db->dropTable( $table, __METHOD__ );
 				$this->output( "done.\n" );
+			} else {
+				return $this->applyPatch( $patch, $fullpath, $msg );
 			}
-			else {
-				$this->applyPatch( $patch, $fullpath, $msg );
-			}
-
 		} else {
 			$this->output( "...$table doesn't exist.\n" );
 		}
+
+		return true;
 	}
 
 	/**
 	 * Modify an existing field
 	 *
-	 * @param $table String: name of the table to which the field belongs
-	 * @param $field String: name of the field to modify
-	 * @param $patch String: path to the patch file
+	 * @param string $table name of the table to which the field belongs
+	 * @param string $field name of the field to modify
+	 * @param string $patch path to the patch file
 	 * @param $fullpath Boolean: whether to treat $patch path as a relative or not
+	 * @return Boolean false if this was skipped because schema changes are skipped
 	 */
 	public function modifyField( $table, $field, $patch, $fullpath = false ) {
+		if ( !$this->doTable( $table ) ) {
+			return true;
+		}
+
 		$updateKey = "$table-$field-$patch";
 		if ( !$this->db->tableExists( $table, __METHOD__ ) ) {
 			$this->output( "...$table table does not exist, skipping modify field patch.\n" );
 		} elseif ( !$this->db->fieldExists( $table, $field, __METHOD__ ) ) {
-			$this->output( "...$field field does not exist in $table table, skipping modify field patch.\n" );
-		} elseif( $this->updateRowExists( $updateKey ) ) {
+			$this->output( "...$field field does not exist in $table table, " .
+				"skipping modify field patch.\n" );
+		} elseif ( $this->updateRowExists( $updateKey ) ) {
 			$this->output( "...$field in table $table already modified by patch $patch.\n" );
 		} else {
-			$this->applyPatch( $patch, $fullpath, "Modifying $field field of table $table" );
 			$this->insertUpdateRow( $updateKey );
+
+			return $this->applyPatch( $patch, $fullpath, "Modifying $field field of table $table" );
 		}
+
+		return true;
 	}
 
 	/**
 	 * Purge the objectcache table
 	 */
-	protected function purgeCache() {
+	public function purgeCache() {
+		global $wgLocalisationCacheConf;
 		# We can't guarantee that the user will be able to use TRUNCATE,
 		# but we know that DELETE is available to us
 		$this->output( "Purging caches..." );
 		$this->db->delete( 'objectcache', '*', __METHOD__ );
+		if ( $wgLocalisationCacheConf['manualRecache'] ) {
+			$this->rebuildLocalisationCache();
+		}
+		MessageBlobStore::clear();
 		$this->output( "done.\n" );
 	}
 
@@ -630,6 +911,7 @@ abstract class DatabaseUpdater {
 			$this->output( "missing ss_total_pages, rebuilding...\n" );
 		} else {
 			$this->output( "done.\n" );
+
 			return;
 		}
 		SiteStatsInit::doAllAndCommit( $this->db );
@@ -661,9 +943,10 @@ abstract class DatabaseUpdater {
 	protected function doLogUsertextPopulation() {
 		if ( !$this->updateRowExists( 'populate log_usertext' ) ) {
 			$this->output(
-			"Populating log_user_text field, printing progress markers. For large\n" .
-			"databases, you may want to hit Ctrl-C and do this manually with\n" .
-			"maintenance/populateLogUsertext.php.\n" );
+				"Populating log_user_text field, printing progress markers. For large\n" .
+				"databases, you may want to hit Ctrl-C and do this manually with\n" .
+				"maintenance/populateLogUsertext.php.\n"
+			);
 
 			$task = $this->maintenance->runChild( 'PopulateLogUsertext' );
 			$task->execute();
@@ -693,10 +976,12 @@ abstract class DatabaseUpdater {
 	protected function doUpdateTranscacheField() {
 		if ( $this->updateRowExists( 'convert transcache field' ) ) {
 			$this->output( "...transcache tc_time already converted.\n" );
-			return;
+
+			return true;
 		}
 
-		$this->applyPatch( 'patch-tc-timestamp.sql', false, "Converting tc_time from UNIX epoch to MediaWiki timestamp" );
+		return $this->applyPatch( 'patch-tc-timestamp.sql', false,
+			"Converting tc_time from UNIX epoch to MediaWiki timestamp" );
 	}
 
 	/**
@@ -704,29 +989,35 @@ abstract class DatabaseUpdater {
 	 */
 	protected function doCollationUpdate() {
 		global $wgCategoryCollation;
-		if ( $this->db->selectField(
-			'categorylinks',
-			'COUNT(*)',
-			'cl_collation != ' . $this->db->addQuotes( $wgCategoryCollation ),
-			__METHOD__
-		) == 0 ) {
-			$this->output( "...collations up-to-date.\n" );
-			return;
-		}
+		if ( $this->db->fieldExists( 'categorylinks', 'cl_collation', __METHOD__ ) ) {
+			if ( $this->db->selectField(
+				'categorylinks',
+				'COUNT(*)',
+				'cl_collation != ' . $this->db->addQuotes( $wgCategoryCollation ),
+				__METHOD__
+				) == 0
+			) {
+				$this->output( "...collations up-to-date.\n" );
+
+				return;
+			}
 
-		$this->output( "Updating category collations..." );
-		$task = $this->maintenance->runChild( 'UpdateCollation' );
-		$task->execute();
-		$this->output( "...done.\n" );
+			$this->output( "Updating category collations..." );
+			$task = $this->maintenance->runChild( 'UpdateCollation' );
+			$task->execute();
+			$this->output( "...done.\n" );
+		}
 	}
 
 	/**
 	 * Migrates user options from the user table blob to user_properties
 	 */
 	protected function doMigrateUserOptions() {
-		$cl = $this->maintenance->runChild( 'ConvertUserOptions', 'convertUserOptions.php' );
-		$cl->execute();
-		$this->output( "done.\n" );
+		if ( $this->db->tableExists( 'user_properties' ) ) {
+			$cl = $this->maintenance->runChild( 'ConvertUserOptions', 'convertUserOptions.php' );
+			$cl->execute();
+			$this->output( "done.\n" );
+		}
 	}
 
 	/**