NOISSUE Fix jar mods for OnesSix

23 files changed, 436 insertions, 881 deletions

diff --git a/logic/BaseInstance.cpp b/logic/BaseInstance.cpp
index 1dc5b671..b23dde73 100644
--- a/logic/BaseInstance.cpp
+++ b/logic/BaseInstance.cpp
@@ -15,7 +15,6 @@
 
 #include "MultiMC.h"
 #include "BaseInstance.h"
-#include "BaseInstance_p.h"
 
 #include <QFileInfo>
 #include <QDir>
@@ -31,61 +30,50 @@
 #include "logic/icons/IconList.h"
 #include "logic/InstanceList.h"
 
-BaseInstance::BaseInstance(BaseInstancePrivate *d_in, const QString &rootDir,
-						   SettingsObject *settings_obj, QObject *parent)
-	: QObject(parent), inst_d(d_in)
+BaseInstance::BaseInstance(const QString &rootDir, SettingsObject *settings, QObject *parent)
+	: QObject(parent)
 {
-	I_D(BaseInstance);
-	d->m_settings = std::shared_ptr<SettingsObject>(settings_obj);
-	d->m_rootDir = rootDir;
 
-	settings().registerSetting("name", "Unnamed Instance");
-	settings().registerSetting("iconKey", "default");
+	m_settings = std::shared_ptr<SettingsObject>(settings);
+	m_rootDir = rootDir;
+
+	m_settings->registerSetting("name", "Unnamed Instance");
+	m_settings->registerSetting("iconKey", "default");
 	connect(MMC->icons().get(), SIGNAL(iconUpdated(QString)), SLOT(iconUpdated(QString)));
-	settings().registerSetting("notes", "");
-	settings().registerSetting("lastLaunchTime", 0);
-
-	/*
-	 * custom base jar has no default. it is determined in code... see the accessor methods for
-	 *it
-	 *
-	 * for instances that DO NOT have the CustomBaseJar setting (legacy instances),
-	 * [.]minecraft/bin/mcbackup.jar is the default base jar
-	 */
-	settings().registerSetting("UseCustomBaseJar", true);
-	settings().registerSetting("CustomBaseJar", "");
+	m_settings->registerSetting("notes", "");
+	m_settings->registerSetting("lastLaunchTime", 0);
 
 	auto globalSettings = MMC->settings();
 
 	// Java Settings
-	settings().registerSetting("OverrideJava", false);
-	settings().registerSetting("OverrideJavaLocation", false);
-	settings().registerSetting("OverrideJavaArgs", false);
-	settings().registerOverride(globalSettings->getSetting("JavaPath"));
-	settings().registerOverride(globalSettings->getSetting("JvmArgs"));
+	m_settings->registerSetting("OverrideJava", false);
+	m_settings->registerSetting("OverrideJavaLocation", false);
+	m_settings->registerSetting("OverrideJavaArgs", false);
+	m_settings->registerOverride(globalSettings->getSetting("JavaPath"));
+	m_settings->registerOverride(globalSettings->getSetting("JvmArgs"));
 
 	// Custom Commands
-	settings().registerSetting({"OverrideCommands","OverrideLaunchCmd"}, false);
-	settings().registerOverride(globalSettings->getSetting("PreLaunchCommand"));
-	settings().registerOverride(globalSettings->getSetting("PostExitCommand"));
+	m_settings->registerSetting({"OverrideCommands","OverrideLaunchCmd"}, false);
+	m_settings->registerOverride(globalSettings->getSetting("PreLaunchCommand"));
+	m_settings->registerOverride(globalSettings->getSetting("PostExitCommand"));
 
 	// Window Size
-	settings().registerSetting("OverrideWindow", false);
-	settings().registerOverride(globalSettings->getSetting("LaunchMaximized"));
-	settings().registerOverride(globalSettings->getSetting("MinecraftWinWidth"));
-	settings().registerOverride(globalSettings->getSetting("MinecraftWinHeight"));
+	m_settings->registerSetting("OverrideWindow", false);
+	m_settings->registerOverride(globalSettings->getSetting("LaunchMaximized"));
+	m_settings->registerOverride(globalSettings->getSetting("MinecraftWinWidth"));
+	m_settings->registerOverride(globalSettings->getSetting("MinecraftWinHeight"));
 
 	// Memory
-	settings().registerSetting("OverrideMemory", false);
-	settings().registerOverride(globalSettings->getSetting("MinMemAlloc"));
-	settings().registerOverride(globalSettings->getSetting("MaxMemAlloc"));
-	settings().registerOverride(globalSettings->getSetting("PermGen"));
+	m_settings->registerSetting("OverrideMemory", false);
+	m_settings->registerOverride(globalSettings->getSetting("MinMemAlloc"));
+	m_settings->registerOverride(globalSettings->getSetting("MaxMemAlloc"));
+	m_settings->registerOverride(globalSettings->getSetting("PermGen"));
 
 	// Console
-	settings().registerSetting("OverrideConsole", false);
-	settings().registerOverride(globalSettings->getSetting("ShowConsole"));
-	settings().registerOverride(globalSettings->getSetting("AutoCloseConsole"));
-	settings().registerOverride(globalSettings->getSetting("LogPrePostOutput"));
+	m_settings->registerSetting("OverrideConsole", false);
+	m_settings->registerOverride(globalSettings->getSetting("ShowConsole"));
+	m_settings->registerOverride(globalSettings->getSetting("AutoCloseConsole"));
+	m_settings->registerOverride(globalSettings->getSetting("LogPrePostOutput"));
 }
 
 void BaseInstance::iconUpdated(QString key)
@@ -109,26 +97,22 @@ QString BaseInstance::id() const
 
 bool BaseInstance::isRunning() const
 {
-	I_D(BaseInstance);
-	return d->m_isRunning;
+	return m_isRunning;
 }
 
-void BaseInstance::setRunning(bool running) const
+void BaseInstance::setRunning(bool running)
 {
-	I_D(BaseInstance);
-	d->m_isRunning = running;
+	m_isRunning = running;
 }
 
 QString BaseInstance::instanceType() const
 {
-	I_D(BaseInstance);
-	return d->m_settings->get("InstanceType").toString();
+	return m_settings->get("InstanceType").toString();
 }
 
 QString BaseInstance::instanceRoot() const
 {
-	I_D(BaseInstance);
-	return d->m_rootDir;
+	return m_rootDir;
 }
 
 QString BaseInstance::minecraftRoot() const
@@ -159,36 +143,34 @@ std::shared_ptr<BaseVersionList> BaseInstance::versionList() const
 
 SettingsObject &BaseInstance::settings() const
 {
-	I_D(BaseInstance);
-	return *d->m_settings;
+	return *m_settings;
 }
 
 BaseInstance::InstanceFlags BaseInstance::flags() const
 {
-	I_D(const BaseInstance);
-	return d->m_flags;
+	return m_flags;
 }
+
 void BaseInstance::setFlags(const InstanceFlags &flags)
 {
-	I_D(BaseInstance);
-	if (flags != d->m_flags)
+	if (flags != m_flags)
 	{
-		d->m_flags = flags;
+		m_flags = flags;
 		emit flagsChanged();
 		emit propertiesChanged(this);
 	}
 }
+
 void BaseInstance::setFlag(const BaseInstance::InstanceFlag flag)
 {
-	I_D(BaseInstance);
-	d->m_flags |= flag;
+	m_flags |= flag;
 	emit flagsChanged();
 	emit propertiesChanged(this);
 }
+
 void BaseInstance::unsetFlag(const BaseInstance::InstanceFlag flag)
 {
-	I_D(BaseInstance);
-	d->m_flags &= ~flag;
+	m_flags &= ~flag;
 	emit flagsChanged();
 	emit propertiesChanged(this);
 }
@@ -200,69 +182,23 @@ bool BaseInstance::canLaunch() const
 
 bool BaseInstance::reload()
 {
-	return settings().reload();
-}
-
-QString BaseInstance::baseJar() const
-{
-	I_D(BaseInstance);
-	bool customJar = d->m_settings->get("UseCustomBaseJar").toBool();
-	if (customJar)
-	{
-		return customBaseJar();
-	}
-	else
-		return defaultBaseJar();
-}
-
-QString BaseInstance::customBaseJar() const
-{
-	I_D(BaseInstance);
-	QString value = d->m_settings->get("CustomBaseJar").toString();
-	if (value.isNull() || value.isEmpty())
-	{
-		return defaultCustomBaseJar();
-	}
-	return value;
-}
-
-void BaseInstance::setCustomBaseJar(QString val)
-{
-	I_D(BaseInstance);
-	if (val.isNull() || val.isEmpty() || val == defaultCustomBaseJar())
-		d->m_settings->reset("CustomBaseJar");
-	else
-		d->m_settings->set("CustomBaseJar", val);
-}
-
-void BaseInstance::setShouldUseCustomBaseJar(bool val)
-{
-	I_D(BaseInstance);
-	d->m_settings->set("UseCustomBaseJar", val);
-}
-
-bool BaseInstance::shouldUseCustomBaseJar() const
-{
-	I_D(BaseInstance);
-	return d->m_settings->get("UseCustomBaseJar").toBool();
+	return m_settings->reload();
 }
 
 qint64 BaseInstance::lastLaunch() const
 {
-	I_D(BaseInstance);
-	return d->m_settings->get("lastLaunchTime").value<qint64>();
+	return m_settings->get("lastLaunchTime").value<qint64>();
 }
+
 void BaseInstance::setLastLaunch(qint64 val)
 {
-	I_D(BaseInstance);
-	d->m_settings->set("lastLaunchTime", val);
+	m_settings->set("lastLaunchTime", val);
 	emit propertiesChanged(this);
 }
 
 void BaseInstance::setGroupInitial(QString val)
 {
-	I_D(BaseInstance);
-	d->m_group = val;
+	m_group = val;
 	emit propertiesChanged(this);
 }
 
@@ -274,44 +210,39 @@ void BaseInstance::setGroupPost(QString val)
 
 QString BaseInstance::group() const
 {
-	I_D(BaseInstance);
-	return d->m_group;
+	return m_group;
 }
 
 void BaseInstance::setNotes(QString val)
 {
-	I_D(BaseInstance);
-	d->m_settings->set("notes", val);
+	m_settings->set("notes", val);
 }
+
 QString BaseInstance::notes() const
 {
-	I_D(BaseInstance);
-	return d->m_settings->get("notes").toString();
+	return m_settings->get("notes").toString();
 }
 
 void BaseInstance::setIconKey(QString val)
 {
-	I_D(BaseInstance);
-	d->m_settings->set("iconKey", val);
+	m_settings->set("iconKey", val);
 	emit propertiesChanged(this);
 }
+
 QString BaseInstance::iconKey() const
 {
-	I_D(BaseInstance);
-	return d->m_settings->get("iconKey").toString();
+	return m_settings->get("iconKey").toString();
 }
 
 void BaseInstance::setName(QString val)
 {
-	I_D(BaseInstance);
-	d->m_settings->set("name", val);
+	m_settings->set("name", val);
 	emit propertiesChanged(this);
 }
 
 QString BaseInstance::name() const
 {
-	I_D(BaseInstance);
-	return d->m_settings->get("name").toString();
+	return m_settings->get("name").toString();
 }
 
 QString BaseInstance::windowTitle() const
diff --git a/logic/BaseInstance.h b/logic/BaseInstance.h
index c8517298..a0ac3c57 100644
--- a/logic/BaseInstance.h
+++ b/logic/BaseInstance.h
@@ -51,8 +51,7 @@ class BaseInstance : public QObject
 	Q_OBJECT
 protected:
 	/// no-touchy!
-	BaseInstance(BaseInstancePrivate *d, const QString &rootDir, SettingsObject *settings,
-				 QObject *parent = 0);
+	BaseInstance(const QString &rootDir, SettingsObject *settings, QObject *parent = 0);
 
 public:
 	/// virtual destructor to make sure the destruction is COMPLETE
@@ -69,8 +68,8 @@ public:
 	/// be unique.
 	virtual QString id() const;
 
-	virtual void setRunning(bool running) const;
-	virtual bool isRunning() const;
+	void setRunning(bool running);
+	bool isRunning() const;
 
 	/// get the type of this instance
 	QString instanceType() const;
@@ -127,30 +126,10 @@ public:
 	{
 		return nullptr;
 	}
-	
+
 	/// Traits. Normally inside the version, depends on instance implementation.
 	virtual QSet <QString> traits() = 0;
 
-	/// Get the curent base jar of this instance. By default, it's the
-	/// versions/$version/$version.jar
-	QString baseJar() const;
-
-	/// the default base jar of this instance
-	virtual QString defaultBaseJar() const = 0;
-	/// the default custom base jar of this instance
-	virtual QString defaultCustomBaseJar() const = 0;
-
-	/*!
-	 * Whether or not custom base jar is used
-	 */
-	bool shouldUseCustomBaseJar() const;
-	void setShouldUseCustomBaseJar(bool val);
-	/*!
-	 * The value of the custom base jar
-	 */
-	QString customBaseJar() const;
-	void setCustomBaseJar(QString val);
-
 	/**
 	 * Gets the time that the instance was last launched.
 	 * Stored in milliseconds since epoch.
@@ -202,7 +181,7 @@ public:
 		VersionBrokenFlag = 0x01,
 		UpdateAvailable = 0x02
 	};
-	Q_DECLARE_FLAGS(InstanceFlags, InstanceFlag)
+	Q_DECLARE_FLAGS(InstanceFlags, InstanceFlag);
 	InstanceFlags flags() const;
 	void setFlags(const InstanceFlags &flags);
 	void setFlag(const InstanceFlag flag);
@@ -232,7 +211,11 @@ protected slots:
 	void iconUpdated(QString key);
 
 protected:
-	std::shared_ptr<BaseInstancePrivate> inst_d;
+	QString m_rootDir;
+	QString m_group;
+	std::shared_ptr<SettingsObject> m_settings;
+	InstanceFlags m_flags;
+	bool m_isRunning = false;
 };
 
 Q_DECLARE_METATYPE(std::shared_ptr<BaseInstance>)
diff --git a/logic/BaseInstance_p.h b/logic/BaseInstance_p.h
deleted file mode 100644
index 2958e4e8..00000000
--- a/logic/BaseInstance_p.h
+++ /dev/null
@@ -1,36 +0,0 @@
-/* Copyright 2013-2014 MultiMC Contributors
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-#pragma once
-
-#include <QString>
-#include <QSet>
-
-#include "logic/settings/SettingsObject.h"
-
-#include "BaseInstance.h"
-
-#define I_D(Class) Class##Private *const d = (Class##Private * const)inst_d.get()
-
-class BaseInstancePrivate
-{
-public:
-    virtual ~BaseInstancePrivate(){};
-	QString m_rootDir;
-	QString m_group;
-	std::shared_ptr<SettingsObject> m_settings;
-	BaseInstance::InstanceFlags m_flags;
-	bool m_isRunning = false;
-};
diff --git a/logic/InstanceFactory.cpp b/logic/InstanceFactory.cpp
index 640c02f3..832b8387 100644
--- a/logic/InstanceFactory.cpp
+++ b/logic/InstanceFactory.cpp
@@ -100,7 +100,6 @@ InstanceFactory::InstCreateError InstanceFactory::createInstance(InstancePtr &in
 		m_settings->set("InstanceType", "OneSix");
 		inst.reset(new OneSixInstance(instDir, m_settings));
 		inst->setIntendedVersionId(version->descriptor());
-		inst->setShouldUseCustomBaseJar(false);
 	}
 	else if (type == FTBInstance)
 	{
@@ -109,14 +108,12 @@ InstanceFactory::InstCreateError InstanceFactory::createInstance(InstancePtr &in
 			m_settings->set("InstanceType", "LegacyFTB");
 			inst.reset(new LegacyFTBInstance(instDir, m_settings));
 			inst->setIntendedVersionId(version->descriptor());
-			inst->setShouldUseCustomBaseJar(false);
 		}
 		else
 		{
 			m_settings->set("InstanceType", "OneSixFTB");
 			inst.reset(new OneSixFTBInstance(instDir, m_settings));
 			inst->setIntendedVersionId(version->descriptor());
-			inst->setShouldUseCustomBaseJar(false);
 		}
 	}
 	else
diff --git a/logic/InstanceLauncher.cpp b/logic/InstanceLauncher.cpp
deleted file mode 100644
index 4e47c592..00000000
--- a/logic/InstanceLauncher.cpp
+++ /dev/null
@@ -1,94 +0,0 @@
-/* Copyright 2013-2014 MultiMC Contributors
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-#include <iostream>
-
-#include "InstanceLauncher.h"
-#include "MultiMC.h"
-
-#include "gui/ConsoleWindow.h"
-#include "gui/dialogs/ProgressDialog.h"
-
-#include "logic/MinecraftProcess.h"
-#include "logic/InstanceList.h"
-
-InstanceLauncher::InstanceLauncher(QString instId) : QObject(), instId(instId)
-{
-}
-
-void InstanceLauncher::onTerminated()
-{
-	std::cout << "Minecraft exited" << std::endl;
-	MMC->quit();
-}
-
-void InstanceLauncher::onLoginComplete()
-{
-	// TODO: Fix this.
-	/*
-	LoginTask *task = (LoginTask *)QObject::sender();
-	auto result = task->getResult();
-	auto instance = MMC->instances()->getInstanceById(instId);
-	proc = instance->prepareForLaunch(result);
-	if (!proc)
-	{
-		// FIXME: report error
-		return;
-	}
-	console = new ConsoleWindow(proc);
-	connect(console, SIGNAL(isClosing()), this, SLOT(onTerminated()));
-
-	proc->setLogin(result.username, result.session_id);
-	proc->launch();
-	*/
-}
-
-void InstanceLauncher::doLogin(const QString &errorMsg)
-{
-	// FIXME: Use new account system here...
-	/*
-	LoginDialog *loginDlg = new LoginDialog(nullptr, errorMsg);
-	loginDlg->exec();
-	if (loginDlg->result() == QDialog::Accepted)
-	{
-		PasswordLogin uInfo{loginDlg->getUsername(), loginDlg->getPassword()};
-
-		ProgressDialog *tDialog = new ProgressDialog(nullptr);
-		LoginTask *loginTask = new LoginTask(uInfo, tDialog);
-		connect(loginTask, SIGNAL(succeeded()), SLOT(onLoginComplete()), Qt::QueuedConnection);
-		connect(loginTask, SIGNAL(failed(QString)), SLOT(doLogin(QString)),
-				Qt::QueuedConnection);
-		tDialog->exec(loginTask);
-	}
-	*/
-	// onLoginComplete(LoginResponse("Offline","Offline", 1));
-}
-
-int InstanceLauncher::launch()
-{
-	std::cout << "Launching Instance '" << qPrintable(instId) << "'" << std::endl;
-	auto instance = MMC->instances()->getInstanceById(instId);
-	if (!instance)
-	{
-		std::cout << "Could not find instance requested. note that you have to specify the ID, "
-					 "not the NAME" << std::endl;
-		return 1;
-	}
-
-	std::cout << "Logging in..." << std::endl;
-	doLogin("");
-
-	return MMC->exec();
-}
diff --git a/logic/InstanceLauncher.h b/logic/InstanceLauncher.h
deleted file mode 100644
index 07f86b99..00000000
--- a/logic/InstanceLauncher.h
+++ /dev/null
@@ -1,44 +0,0 @@
-/* Copyright 2013-2014 MultiMC Contributors
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-#pragma once
-
-#include <QObject>
-
-class MinecraftProcess;
-class ConsoleWindow;
-
-// Commandline instance launcher
-class InstanceLauncher : public QObject
-{
-	Q_OBJECT
-
-private:
-	QString instId;
-	MinecraftProcess *proc;
-	ConsoleWindow *console;
-
-public:
-	InstanceLauncher(QString instId);
-
-private
-slots:
-	void onTerminated();
-	void onLoginComplete();
-	void doLogin(const QString &errorMsg);
-
-public:
-	int launch();
-};
diff --git a/logic/JarUtils.cpp b/logic/JarUtils.cpp
new file mode 100644
index 00000000..3b4f780a
--- /dev/null
+++ b/logic/JarUtils.cpp
@@ -0,0 +1,161 @@
+#include "JarUtils.h"
+#include <quazip.h>
+#include <quazipfile.h>
+#include <JlCompress.h>
+#include <logger/QsLog.h>
+
+namespace JarUtils {
+
+bool mergeZipFiles(QuaZip *into, QFileInfo from, QSet<QString> &contained,
+				   std::function<bool(QString)> filter)
+{
+	QuaZip modZip(from.filePath());
+	modZip.open(QuaZip::mdUnzip);
+
+	QuaZipFile fileInsideMod(&modZip);
+	QuaZipFile zipOutFile(into);
+	for (bool more = modZip.goToFirstFile(); more; more = modZip.goToNextFile())
+	{
+		QString filename = modZip.getCurrentFileName();
+		if (!filter(filename))
+		{
+			QLOG_INFO() << "Skipping file " << filename << " from "
+						<< from.fileName() << " - filtered";
+			continue;
+		}
+		if (contained.contains(filename))
+		{
+			QLOG_INFO() << "Skipping already contained file " << filename << " from "
+						<< from.fileName();
+			continue;
+		}
+		contained.insert(filename);
+		QLOG_INFO() << "Adding file " << filename << " from " << from.fileName();
+
+		if (!fileInsideMod.open(QIODevice::ReadOnly))
+		{
+			QLOG_ERROR() << "Failed to open " << filename << " from " << from.fileName();
+			return false;
+		}
+
+		QuaZipNewInfo info_out(fileInsideMod.getActualFileName());
+
+		if (!zipOutFile.open(QIODevice::WriteOnly, info_out))
+		{
+			QLOG_ERROR() << "Failed to open " << filename << " in the jar";
+			fileInsideMod.close();
+			return false;
+		}
+		if (!JlCompress::copyData(fileInsideMod, zipOutFile))
+		{
+			zipOutFile.close();
+			fileInsideMod.close();
+			QLOG_ERROR() << "Failed to copy data of " << filename << " into the jar";
+			return false;
+		}
+		zipOutFile.close();
+		fileInsideMod.close();
+	}
+	return true;
+}
+
+bool createModdedJar(QString sourceJarPath, QString targetJarPath, const QList<Mod>& mods)
+{
+	QuaZip zipOut(targetJarPath);
+	if (!zipOut.open(QuaZip::mdCreate))
+	{
+		QFile::remove(targetJarPath);
+		QLOG_ERROR() << "Failed to open the minecraft.jar for modding";
+		return false;
+	}
+	// Files already added to the jar.
+	// These files will be skipped.
+	QSet<QString> addedFiles;
+
+	// Modify the jar
+	QListIterator<Mod> i(mods);
+    i.toBack();
+    while (i.hasPrevious())
+	{
+		const Mod &mod = i.previous();
+		// do not merge disabled mods.
+		if (!mod.enabled())
+			continue;
+		if (mod.type() == Mod::MOD_ZIPFILE)
+		{
+			if (!mergeZipFiles(&zipOut, mod.filename(), addedFiles, noFilter))
+			{
+				zipOut.close();
+				QFile::remove(targetJarPath);
+				QLOG_ERROR() << "Failed to add" << mod.filename().fileName() << "to the jar.";
+				return false;
+			}
+		}
+		else if (mod.type() == Mod::MOD_SINGLEFILE)
+		{
+			auto filename = mod.filename();
+			if (!JlCompress::compressFile(&zipOut, filename.absoluteFilePath(),
+										  filename.fileName()))
+			{
+				zipOut.close();
+				QFile::remove(targetJarPath);
+				QLOG_ERROR() << "Failed to add" << mod.filename().fileName() << "to the jar.";
+				return false;
+			}
+			addedFiles.insert(filename.fileName());
+			QLOG_INFO() << "Adding file " << filename.fileName() << " from "
+						<< filename.absoluteFilePath();
+		}
+		else if (mod.type() == Mod::MOD_FOLDER)
+		{
+			auto filename = mod.filename();
+			QString what_to_zip = filename.absoluteFilePath();
+			QDir dir(what_to_zip);
+			dir.cdUp();
+			QString parent_dir = dir.absolutePath();
+			if (!JlCompress::compressSubDir(&zipOut, what_to_zip, parent_dir, true, addedFiles))
+			{
+				zipOut.close();
+				QFile::remove(targetJarPath);
+				QLOG_ERROR() << "Failed to add" << mod.filename().fileName() << "to the jar.";
+				return false;
+			}
+			QLOG_INFO() << "Adding folder " << filename.fileName() << " from "
+						<< filename.absoluteFilePath();
+		}
+	}
+
+	if (!mergeZipFiles(&zipOut, QFileInfo(sourceJarPath), addedFiles, metaInfFilter))
+	{
+		zipOut.close();
+		QFile::remove(targetJarPath);
+		QLOG_ERROR() << "Failed to insert minecraft.jar contents.";
+		return false;
+	}
+
+	// Recompress the jar
+	zipOut.close();
+	if (zipOut.getZipError() != 0)
+	{
+		QFile::remove(targetJarPath);
+		QLOG_ERROR() << "Failed to finalize minecraft.jar!";
+		return false;
+	}
+	return true;
+}
+
+bool noFilter(QString)
+{
+	return true;
+}
+
+bool metaInfFilter(QString key)
+{
+	if(key.contains("META-INF"))
+	{
+		return false;
+	}
+	return true;
+}
+
+}
diff --git a/logic/JarUtils.h b/logic/JarUtils.h
new file mode 100644
index 00000000..2e8bd2a7
--- /dev/null
+++ b/logic/JarUtils.h
@@ -0,0 +1,18 @@
+#pragma once
+#include <QString>
+#include <QFileInfo>
+#include <QSet>
+#include "Mod.h"
+#include <functional>
+
+class QuaZip;
+namespace JarUtils
+{
+	bool noFilter(QString);
+	bool metaInfFilter(QString key);
+
+	bool mergeZipFiles(QuaZip *into, QFileInfo from, QSet<QString> &contained,
+				   std::function<bool(QString)> filter);
+
+	bool createModdedJar(QString sourceJarPath, QString targetJarPath, const QList<Mod>& mods);
+}
diff --git a/logic/LegacyInstance.cpp b/logic/LegacyInstance.cpp
index 468110da..7752229a 100644
--- a/logic/LegacyInstance.cpp
+++ b/logic/LegacyInstance.cpp
@@ -23,7 +23,6 @@
 #include "MultiMC.h"
 
 #include "LegacyInstance.h"
-#include "LegacyInstance_p.h"
 
 #include "logic/MinecraftProcess.h"
 #include "logic/LegacyUpdate.h"
@@ -36,15 +35,23 @@
 #include <gui/pages/NotesPage.h>
 #include <gui/pages/ScreenshotsPage.h>
 
-LegacyInstance::LegacyInstance(const QString &rootDir, SettingsObject *settings,
-							   QObject *parent)
-	: BaseInstance(new LegacyInstancePrivate(), rootDir, settings, parent)
+LegacyInstance::LegacyInstance(const QString &rootDir, SettingsObject *settings, QObject *parent)
+	: BaseInstance(rootDir, settings, parent)
 {
 	settings->registerSetting("NeedsRebuild", true);
 	settings->registerSetting("ShouldUpdate", false);
 	settings->registerSetting("JarVersion", "Unknown");
 	settings->registerSetting("LwjglVersion", "2.9.0");
 	settings->registerSetting("IntendedJarVersion", "");
+	/*
+	 * custom base jar has no default. it is determined in code... see the accessor methods for
+	 *it
+	 *
+	 * for instances that DO NOT have the CustomBaseJar setting (legacy instances),
+	 * [.]minecraft/bin/mcbackup.jar is the default base jar
+	 */
+	settings->registerSetting("UseCustomBaseJar", true);
+	settings->registerSetting("CustomBaseJar", "");
 }
 
 QList<BasePage *> LegacyInstance::getPages()
@@ -69,6 +76,46 @@ QString LegacyInstance::dialogTitle()
 	return tr("Edit Instance (%1)").arg(name());
 }
 
+QString LegacyInstance::baseJar() const
+{
+	bool customJar = m_settings->get("UseCustomBaseJar").toBool();
+	if (customJar)
+	{
+		return customBaseJar();
+	}
+	else
+		return defaultBaseJar();
+}
+
+QString LegacyInstance::customBaseJar() const
+{
+	QString value = m_settings->get("CustomBaseJar").toString();
+	if (value.isNull() || value.isEmpty())
+	{
+		return defaultCustomBaseJar();
+	}
+	return value;
+}
+
+void LegacyInstance::setCustomBaseJar(QString val)
+{
+	if (val.isNull() || val.isEmpty() || val == defaultCustomBaseJar())
+		m_settings->reset("CustomBaseJar");
+	else
+		m_settings->set("CustomBaseJar", val);
+}
+
+void LegacyInstance::setShouldUseCustomBaseJar(bool val)
+{
+	m_settings->set("UseCustomBaseJar", val);
+}
+
+bool LegacyInstance::shouldUseCustomBaseJar() const
+{
+	return m_settings->get("UseCustomBaseJar").toBool();
+}
+
+
 std::shared_ptr<Task> LegacyInstance::doUpdate()
 {
 	// make sure the jar mods list is initialized by asking for it.
@@ -113,26 +160,24 @@ void LegacyInstance::cleanupAfterRun()
 
 std::shared_ptr<ModList> LegacyInstance::coreModList()
 {
-	I_D(LegacyInstance);
-	if (!d->core_mod_list)
+	if (!core_mod_list)
 	{
-		d->core_mod_list.reset(new ModList(coreModsDir()));
+		core_mod_list.reset(new ModList(coreModsDir()));
 	}
-	d->core_mod_list->update();
-	return d->core_mod_list;
+	core_mod_list->update();
+	return core_mod_list;
 }
 
 std::shared_ptr<ModList> LegacyInstance::jarModList()
 {
-	I_D(LegacyInstance);
-	if (!d->jar_mod_list)
+	if (!jar_mod_list)
 	{
 		auto list = new ModList(jarModsDir(), modListFile());
 		connect(list, SIGNAL(changed()), SLOT(jarModsChanged()));
-		d->jar_mod_list.reset(list);
+		jar_mod_list.reset(list);
 	}
-	d->jar_mod_list->update();
-	return d->jar_mod_list;
+	jar_mod_list->update();
+	return jar_mod_list;
 }
 
 void LegacyInstance::jarModsChanged()
@@ -143,24 +188,22 @@ void LegacyInstance::jarModsChanged()
 
 std::shared_ptr<ModList> LegacyInstance::loaderModList()
 {
-	I_D(LegacyInstance);
-	if (!d->loader_mod_list)
+	if (!loader_mod_list)
 	{
-		d->loader_mod_list.reset(new ModList(loaderModsDir()));
+		loader_mod_list.reset(new ModList(loaderModsDir()));
 	}
-	d->loader_mod_list->update();
-	return d->loader_mod_list;