From 581b2306af81a74a3ce2f3d0611fc76a13bc90ea Mon Sep 17 00:00:00 2001
From: Brad Jorsch <bjorsch@wikimedia.org>
Date: Fri, 12 Apr 2013 10:38:14 -0400
Subject: [PATCH] Remove mw.getLogBuffer and others from public interface

One of the design goals of Scribunto is that each #invoke should be
independent. Creative use of mw.log and mw.getLogBuffer can get around
this, passing information from one #invoke to the next.

This patch takes the simple solution of removing mw.getLogBuffer from
modules' environments. For good measure, it also removes
mw.clearLogBuffer and mw.executeModule.

Some minor cleanup of the console code is also included.

Change-Id: I30d73928bade4a6bdd7c00ffcd58a3858ff55698
---
 engines/LuaCommon/LuaCommon.php | 15 ++++++++-------
 engines/LuaCommon/lualib/mw.lua | 10 ++++++++--
 2 files changed, 16 insertions(+), 9 deletions(-)

diff --git a/engines/LuaCommon/LuaCommon.php b/engines/LuaCommon/LuaCommon.php
index fc382134..bd2bd6b5 100644
--- a/engines/LuaCommon/LuaCommon.php
+++ b/engines/LuaCommon/LuaCommon.php
@@ -27,7 +27,7 @@ abstract class Scribunto_LuaEngine extends ScribuntoEngineBase {
 	);
 
 	protected $loaded = false;
-	protected $executeModuleFunc, $interpreter;
+	protected $interpreter;
 	protected $mw;
 	protected $currentFrames = array();
 	protected $expandCache = array();
@@ -52,7 +52,6 @@ abstract class Scribunto_LuaEngine extends ScribuntoEngineBase {
 	public function destroy() {
 		// Break reference cycles
 		$this->interpreter = null;
-		$this->executeModuleFunc = null;
 		$this->mw = null;
 		$this->expandCache = null;
 		$this->loadedLibraries = null;
@@ -232,8 +231,9 @@ abstract class Scribunto_LuaEngine extends ScribuntoEngineBase {
 			 * Maybe each console line could be evaluated as a different chunk, 
 			 * apparently that's what lua.c does.
 			 */
-			$code = "return function (__init)\n" .
-				"local p = mw.executeModule(__init)\n" .
+			$code = "return function (__init, exe)\n" .
+				"local p = exe(__init)\n" .
+				"__init, exe = nil, nil\n" .
 				"local print = mw.log\n";
 			foreach ( $params['prevQuestions'] as $q ) {
 				if ( substr( $q, 0, 1 ) === '=' ) {
@@ -246,7 +246,8 @@ abstract class Scribunto_LuaEngine extends ScribuntoEngineBase {
 			$code .= "mw.clearLogBuffer()\n";
 			if ( substr( $params['question'], 0, 1 ) === '=' ) {
 				// Treat a statement starting with "=" as a return statement, like in lua.c
-				$code .= "return mw.allToString(" . substr( $params['question'], 1 ) . "), mw.getLogBuffer()\n";
+				$code .= "local ret = mw.allToString(" . substr( $params['question'], 1 ) . ")\n" .
+					"return ret, mw.getLogBuffer()\n";
 			} else {
 				$code .= $params['question'] . "\n" .
 					"return nil, mw.getLogBuffer()\n";
@@ -262,9 +263,9 @@ abstract class Scribunto_LuaEngine extends ScribuntoEngineBase {
 				wfMessage( 'scribunto-console-current-src' )->text()
 			);
 			$consoleInit = $consoleModule->getInitChunk();
-			$ret = $this->executeModule( $consoleInit );
+			$ret = $this->getInterpreter()->callFunction( $this->mw['executeModule'], $consoleInit, true );
 			$func = $ret[0];
-			$ret = $this->getInterpreter()->callFunction( $func, $contentInit );
+			$ret = $this->getInterpreter()->callFunction( $func, $contentInit, $this->mw['executeModule'] );
 		} catch ( Exception $ex ) {
 			$this->currentFrames = $oldFrames;
 			throw $ex;
diff --git a/engines/LuaCommon/lualib/mw.lua b/engines/LuaCommon/lualib/mw.lua
index 7cc0c216..c83051c4 100644
--- a/engines/LuaCommon/lualib/mw.lua
+++ b/engines/LuaCommon/lualib/mw.lua
@@ -133,12 +133,18 @@ end
 -- {{#invoke}}.
 --
 -- @param chunk The module chunk
-function mw.executeModule( chunk )
+-- @param isConsole Whether this is the debug console
+function mw.executeModule( chunk, isConsole )
 	local env = mw.clone( _G )
 	makePackageModule( env )
 
-	-- This is unsafe
+	-- These are unsafe
 	env.mw.makeProtectedEnvFuncs = nil
+	env.mw.executeModule = nil
+	if not isConsole then
+		env.mw.getLogBuffer = nil
+		env.mw.clearLogBuffer = nil
+	end
 
 	if allowEnvFuncs then
 		env.setfenv, env.getfenv = mw.makeProtectedEnvFuncs( {[_G] = true}, {} )