Much change, very jarmod.

46 files changed, 3735 insertions, 142 deletions

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 4617020a..4309c55f 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -374,6 +374,10 @@ SET(MULTIMC_SOURCES
 	logic/Mod.cpp
 	logic/ModList.h
 	logic/ModList.cpp
+	
+	# sets and maps for deciding based on versions
+	logic/VersionFilterData.h
+	logic/VersionFilterData.cpp
 
 	# Basic instance launcher for starting from terminal
 	logic/InstanceLauncher.h
@@ -545,8 +549,6 @@ SET(MULTIMC_SOURCES
 	logic/tools/JVisualVM.cpp
 	
 	# Forge and all things forge related
-	logic/forge/ForgeData.h
-	logic/forge/ForgeData.cpp
 	logic/forge/ForgeVersion.h
 	logic/forge/ForgeVersion.cpp
 	logic/forge/ForgeVersionList.h
@@ -566,6 +568,10 @@ SET(MULTIMC_SOURCES
 	logic/liteloader/LiteLoaderInstaller.cpp
 	logic/liteloader/LiteLoaderVersionList.h
 	logic/liteloader/LiteLoaderVersionList.cpp
+	
+	# MultiMC URN resolver
+	logic/URNResolver.cpp
+	logic/URNResolver.h
 )
 
 
diff --git a/MultiMC.cpp b/MultiMC.cpp
index 28fe8e26..6b5545c1 100644
--- a/MultiMC.cpp
+++ b/MultiMC.cpp
@@ -38,6 +38,8 @@
 #include "logic/tools/JVisualVM.h"
 #include "logic/tools/MCEditTool.h"
 
+#include "logic/URNResolver.h"
+
 #include "pathutils.h"
 #include "cmdutils.h"
 #include <inisettingsobject.h>
@@ -644,6 +646,16 @@ std::shared_ptr<JavaVersionList> MultiMC::javalist()
 	return m_javalist;
 }
 
+std::shared_ptr<URNResolver> MultiMC::resolver()
+{
+	if (!m_resolver)
+	{
+		m_resolver.reset(new URNResolver());
+	}
+	return m_resolver;
+}
+
+
 void MultiMC::installUpdates(const QString updateFilesDir, UpdateFlags flags)
 {
 	// if we are going to update on exit, save the params now
diff --git a/MultiMC.h b/MultiMC.h
index 0fd60b7d..a80a54c6 100644
--- a/MultiMC.h
+++ b/MultiMC.h
@@ -23,6 +23,7 @@ class NewsChecker;
 class StatusChecker;
 class BaseProfilerFactory;
 class BaseDetachedToolFactory;
+class URNResolver;
 
 #if defined(MMC)
 #undef MMC
@@ -128,6 +129,8 @@ public:
 
 	std::shared_ptr<JavaVersionList> javalist();
 
+	std::shared_ptr<URNResolver> resolver();
+
 	QMap<QString, std::shared_ptr<BaseProfilerFactory>> profilers()
 	{
 		return m_profilers;
@@ -214,8 +217,11 @@ private:
 	std::shared_ptr<LiteLoaderVersionList> m_liteloaderlist;
 	std::shared_ptr<MinecraftVersionList> m_minecraftlist;
 	std::shared_ptr<JavaVersionList> m_javalist;
+	std::shared_ptr<URNResolver> m_resolver;
+
 	QMap<QString, std::shared_ptr<BaseProfilerFactory>> m_profilers;
 	QMap<QString, std::shared_ptr<BaseDetachedToolFactory>> m_tools;
+
 	QsLogging::DestinationPtr m_fileDestination;
 	QsLogging::DestinationPtr m_debugDestination;
 
diff --git a/depends/launcher/org/multimc/onesix/OneSixLauncher.java b/depends/launcher/org/multimc/onesix/OneSixLauncher.java
index 28f8e6ee..a908f6f3 100644
--- a/depends/launcher/org/multimc/onesix/OneSixLauncher.java
+++ b/depends/launcher/org/multimc/onesix/OneSixLauncher.java
@@ -38,6 +38,7 @@ public class OneSixLauncher implements Launcher
 		List<String> extlibs;
 		List<String> mcparams;
 		List<String> mods;
+		List<String> traits;
 		String mainClass;
 		String natives;
 		final String windowTitle;
@@ -49,6 +50,7 @@ public class OneSixLauncher implements Launcher
 			mcparams = params.all("param");
 			mainClass = params.first("mainClass");
 			mods = params.allSafe("mods", new ArrayList<String>());
+			traits = params.allSafe("traits", new ArrayList<String>());
 			natives = params.first("natives");
 
 			windowTitle = params.first("windowTitle");
diff --git a/gui/dialogs/InstanceEditDialog.cpp b/gui/dialogs/InstanceEditDialog.cpp
index fe2d1b03..a74f3dcb 100644
--- a/gui/dialogs/InstanceEditDialog.cpp
+++ b/gui/dialogs/InstanceEditDialog.cpp
@@ -262,45 +262,6 @@ void InstanceEditDialog::on_moveLibraryDownBtn_clicked()
 	}
 }
 
-// FIXME: use this for legacy forge... or abstract away.
-/*
-void LegacyModEditDialog::on_addForgeBtn_clicked()
-{
-	VersionSelectDialog vselect(MMC->forgelist().get(), tr("Select Forge version"), this);
-	vselect.setFilter(1, m_inst->intendedVersionId());
-	if (vselect.exec() && vselect.selectedVersion())
-	{
-		ForgeVersionPtr forge =
-			std::dynamic_pointer_cast<ForgeVersion>(vselect.selectedVersion());
-		if (!forge)
-			return;
-		auto entry = MMC->metacache()->resolveEntry("minecraftforge", forge->filename);
-		if (entry->stale)
-		{
-			NetJob *fjob = new NetJob("Forge download");
-			fjob->addNetAction(CacheDownload::make(forge->universal_url, entry));
-			ProgressDialog dlg(this);
-			dlg.exec(fjob);
-			if (dlg.result() == QDialog::Accepted)
-			{
-				m_jarmods->stopWatching();
-				m_jarmods->installMod(QFileInfo(entry->getFullPath()));
-				m_jarmods->startWatching();
-			}
-			else
-			{
-				// failed to download forge :/
-			}
-		}
-		else
-		{
-			m_jarmods->stopWatching();
-			m_jarmods->installMod(QFileInfo(entry->getFullPath()));
-			m_jarmods->startWatching();
-		}
-	}
-}*/
-
 void InstanceEditDialog::on_changeMCVersionBtn_clicked()
 {
 	VersionSelectDialog vselect(m_inst->versionList().get(), tr("Change Minecraft version"), this);
@@ -343,24 +304,6 @@ void InstanceEditDialog::on_changeMCVersionBtn_clicked()
 	tDialog.exec(updateTask.get());
 }
 
-/*
-void MainWindow::on_actionChangeInstLWJGLVersion_triggered()
-{
-	if (!m_selectedInstance)
-		return;
-
-	LWJGLSelectDialog lselect(this);
-	lselect.exec();
-	if (lselect.result() == QDialog::Accepted)
-	{
-        auto ptr = std::dynamic_pointer_cast<LegacyInstance>(m_selectedInstance);
-        if(ptr)
-            ptr->setLWJGLVersion(lselect.selectedVersion());
-	}
-}
-*/
-
-
 void InstanceEditDialog::on_forgeBtn_clicked()
 {
 	// FIXME: use actual model, not reloading. Move logic to model.
diff --git a/logic/BaseInstance.h b/logic/BaseInstance.h
index 16791592..41ceda39 100644
--- a/logic/BaseInstance.h
+++ b/logic/BaseInstance.h
@@ -89,7 +89,7 @@ public:
 	void setGroupInitial(QString val);
 	void setGroupPost(QString val);
 
-	QStringList extraArguments() const;
+	virtual QStringList extraArguments() const;
 
 	virtual QString intendedVersionId() const = 0;
 	virtual bool setIntendedVersionId(QString version) = 0;
diff --git a/logic/LegacyUpdate.cpp b/logic/LegacyUpdate.cpp
index 6816df40..aea88c95 100644
--- a/logic/LegacyUpdate.cpp
+++ b/logic/LegacyUpdate.cpp
@@ -64,7 +64,7 @@ void LegacyUpdate::fmllibsStart()
 	bool forge_present = false;
 
 	QString version = inst->intendedVersionId();
-	auto & fmlLibsMapping = g_forgeData.fmlLibsMapping;
+	auto & fmlLibsMapping = g_VersionFilterData.fmlLibsMapping;
 	if (!fmlLibsMapping.contains(version))
 	{
 		lwjglStart();
diff --git a/logic/LegacyUpdate.h b/logic/LegacyUpdate.h
index 1550ec34..140ee1e3 100644
--- a/logic/LegacyUpdate.h
+++ b/logic/LegacyUpdate.h
@@ -21,7 +21,7 @@
 
 #include "logic/net/NetJob.h"
 #include "logic/tasks/Task.h"
-#include "logic/forge/ForgeData.h"
+#include "logic/VersionFilterData.h"
 
 class MinecraftVersion;
 class BaseInstance;
diff --git a/logic/OneSixInstance.cpp b/logic/OneSixInstance.cpp
index dc452188..9057a6e3 100644
--- a/logic/OneSixInstance.cpp
+++ b/logic/OneSixInstance.cpp
@@ -29,7 +29,8 @@
 #include "gui/dialogs/InstanceEditDialog.h"
 #include <MMCError.h>
 
-OneSixInstance::OneSixInstance(const QString &rootDir, SettingsObject *settings, QObject *parent)
+OneSixInstance::OneSixInstance(const QString &rootDir, SettingsObject *settings,
+							   QObject *parent)
 	: BaseInstance(new OneSixInstancePrivate(), rootDir, settings, parent)
 {
 	I_D(OneSixInstance);
@@ -47,7 +48,7 @@ void OneSixInstance::init()
 		{
 			reloadVersion();
 		}
-		catch(MMCError & e)
+		catch (MMCError &e)
 		{
 			// QLOG_ERROR() << "Caught exception on instance init: " << e.cause();
 		}
@@ -125,7 +126,7 @@ QDir OneSixInstance::reconstructAssets(std::shared_ptr<VersionFinal> version)
 			QString original_path =
 				PathCombine(PathCombine(objectDir.path(), tlk), asset_object.hash);
 			QFile original(original_path);
-			if(!original.exists())
+			if (!original.exists())
 				continue;
 			if (!target.exists())
 			{
@@ -137,7 +138,7 @@ QDir OneSixInstance::reconstructAssets(std::shared_ptr<VersionFinal> version)
 
 				bool couldCopy = original.copy(target_path);
 				QLOG_DEBUG() << " Copying" << original_path << "to" << target_path
-								<< QString::number(couldCopy); // << original.errorString();
+							 << QString::number(couldCopy); // << original.errorString();
 			}
 		}
 
@@ -205,8 +206,20 @@ bool OneSixInstance::prepareForLaunch(AuthSessionPtr account, QString &launchScr
 		{
 			launchScript += "cp " + librariesPath().absoluteFilePath(lib->storagePath()) + "\n";
 		}
-		QString targetstr = version->id + "/" + version->id + ".jar";
-		launchScript += "cp " + versionsPath().absoluteFilePath(targetstr) + "\n";
+		QString minecraftjarpath;
+		if (version->hasJarMods())
+		{
+			for (auto jarmod : version->jarMods)
+			{
+				launchScript += "cp " + jarmodsPath().absoluteFilePath(jarmod->name) + "\n";
+			}
+			minecraftjarpath = version->id + "/" + version->id + "-stripped.jar";
+		}
+		else
+		{
+			minecraftjarpath = version->id + "/" + version->id + ".jar";
+		}
+		launchScript += "cp " + versionsPath().absoluteFilePath(minecraftjarpath) + "\n";
 	}
 	launchScript += "mainClass " + version->mainClass + "\n";
 
@@ -231,12 +244,16 @@ bool OneSixInstance::prepareForLaunch(AuthSessionPtr account, QString &launchScr
 	}
 	QDir natives_dir(PathCombine(instanceRoot(), "natives/"));
 	launchScript += "windowTitle " + windowTitle() + "\n";
-	for(auto native: version->getActiveNativeLibs())
+	for (auto native : version->getActiveNativeLibs())
 	{
 		QFileInfo finfo(PathCombine("libraries", native->storagePath()));
 		launchScript += "ext " + finfo.absoluteFilePath() + "\n";
 	}
 	launchScript += "natives " + natives_dir.absolutePath() + "\n";
+	for (auto trait : version->traits)
+	{
+		launchScript += "trait " + trait + "\n";
+	}
 	launchScript += "launcher onesix\n";
 	return true;
 }
@@ -319,7 +336,7 @@ bool OneSixInstance::versionIsCustom()
 {
 	I_D(const OneSixInstance);
 	auto ver = d->version;
-	if(ver)
+	if (ver)
 	{
 		return !ver->isVanilla();
 	}
@@ -330,7 +347,7 @@ bool OneSixInstance::versionIsFTBPack()
 {
 	I_D(const OneSixInstance);
 	auto ver = d->version;
-	if(ver)
+	if (ver)
 	{
 		return ver->hasFtbPack();
 	}
@@ -352,11 +369,11 @@ void OneSixInstance::reloadVersion()
 		d->m_flags.remove(VersionBrokenFlag);
 		emit versionReloaded();
 	}
-	catch(MMCError & error)
+	catch (MMCError &error)
 	{
 		d->version->clear();
 		d->m_flags.insert(VersionBrokenFlag);
-		//TODO: rethrow to show some error message(s)?
+		// TODO: rethrow to show some error message(s)?
 		emit versionReloaded();
 		throw;
 	}
@@ -409,8 +426,8 @@ QString OneSixInstance::getStatusbarDescription()
 	{
 		traits.append(tr("broken"));
 	}
-	
-	if(traits.size())
+
+	if (traits.size())
 	{
 		return tr("Minecraft %1 (%2)").arg(intendedVersionId()).arg(traits.join(", "));
 	}
@@ -424,6 +441,12 @@ QDir OneSixInstance::librariesPath() const
 {
 	return QDir::current().absoluteFilePath("libraries");
 }
+
+QDir OneSixInstance::jarmodsPath() const
+{
+	return QDir(jarModsDir());
+}
+
 QDir OneSixInstance::versionsPath() const
 {
 	return QDir::current().absoluteFilePath("versions");
@@ -441,7 +464,7 @@ bool OneSixInstance::providesVersionFile() const
 
 bool OneSixInstance::reload()
 {
-	if(BaseInstance::reload())
+	if (BaseInstance::reload())
 	{
 		try
 		{
@@ -480,3 +503,22 @@ QString OneSixInstance::jarModsDir() const
 {
 	return PathCombine(instanceRoot(), "jarmods");
 }
+
+QString OneSixInstance::libDir() const
+{
+	return PathCombine(minecraftRoot(), "lib");
+}
+
+QStringList OneSixInstance::extraArguments() const
+{
+	auto list = BaseInstance::extraArguments();
+	auto version = getFullVersion();
+	if (!version)
+		return list;
+	if (version->hasJarMods())
+	{
+		list.append({"-Dfml.ignoreInvalidMinecraftCertificates=true",
+					 "-Dfml.ignorePatchDiscrepancies=true"});
+	}
+	return list;
+}
diff --git a/logic/OneSixInstance.h b/logic/OneSixInstance.h
index b26ff752..80b197c4 100644
--- a/logic/OneSixInstance.h
+++ b/logic/OneSixInstance.h
@@ -40,6 +40,7 @@ public:
 	QString resourcePacksDir() const;
 	QString loaderModsDir() const;
 	QString coreModsDir() const;
+	QString libDir() const;
 	virtual QString instanceConfigFolder() const override;
 
 	virtual std::shared_ptr<Task> doUpdate() override;
@@ -82,13 +83,15 @@ public:
 	virtual bool menuActionEnabled(QString action_name) const override;
 	virtual QString getStatusbarDescription() override;
 
+	virtual QDir jarmodsPath() const;
 	virtual QDir librariesPath() const;
 	virtual QDir versionsPath() const;
 	virtual QStringList externalPatches() const;
 	virtual bool providesVersionFile() const;
 
 	bool reload() override;
-
+	virtual QStringList extraArguments() const override;
+	
 signals:
 	void versionReloaded();
 
diff --git a/logic/OneSixUpdate.cpp b/logic/OneSixUpdate.cpp
index da2fd29c..230ef9a9 100644
--- a/logic/OneSixUpdate.cpp
+++ b/logic/OneSixUpdate.cpp
@@ -259,7 +259,7 @@ void OneSixUpdate::jarlibStart()
 		auto metacache = MMC->metacache();
 		auto entry = metacache->resolveEntry("versions", localPath);
 		job->addNetAction(CacheDownload::make(QUrl(urlstr), entry));
-
+		jarHashOnEntry = entry->md5sum;
 		jarlibDownloadJob.reset(job);
 	}
 
@@ -341,7 +341,36 @@ void OneSixUpdate::jarlibStart()
 
 void OneSixUpdate::jarlibFinished()
 {
-	assetIndexStart();
+	OneSixInstance *inst = (OneSixInstance *)m_inst;
+	std::shared_ptr<VersionFinal> version = inst->getFullVersion();
+	
+	// create stripped jar, if needed
+	if(version->hasJarMods())
+	{
+		//FIXME: good candidate for moving elsewhere (jar location resolving/version caching).
+		QString version_id = version->id;
+		QString localPath = version_id + "/" + version_id + ".jar";
+		QString strippedPath = version_id + "/" + version_id + "-stripped.jar";
+		auto metacache = MMC->metacache();
+		auto entry = metacache->resolveEntry("versions", localPath);
+		auto entryStripped = metacache->resolveEntry("versions", strippedPath);
+		
+		QString fullJarPath = entry->getFullPath();
+		QString fullStrippedJarPath = entryStripped->getFullPath();
+		
+		if(entry->md5sum != jarHashOnEntry || !QFileInfo::exists(fullStrippedJarPath))
+		{
+			stripJar(fullJarPath, fullStrippedJarPath);
+		}
+	}
+	if(version->traits.contains("legacyFML"))
+	{
+		fmllibsStart();
+	}
+	else
+	{
+		assetIndexStart();
+	}
 }
 
 void OneSixUpdate::jarlibFailed()
@@ -350,3 +379,184 @@ void OneSixUpdate::jarlibFailed()
 	QString failed_all = failed.join("\n");
 	emitFailed(tr("Failed to download the following files:\n%1\n\nPlease try again.").arg(failed_all));
 }
+
+void OneSixUpdate::stripJar(QString origPath, QString newPath)
+{
+	QFileInfo runnableJar(newPath);
+	if (runnableJar.exists() && !QFile::remove(runnableJar.filePath()))
+	{
+		emitFailed("Failed to delete old minecraft.jar");
+		return;
+	}
+
+	// TaskStep(); // STEP 1
+	setStatus(tr("Creating stripped jar: Opening minecraft.jar ..."));
+
+	QuaZip zipOut(runnableJar.filePath());
+	if (!zipOut.open(QuaZip::mdCreate))
+	{
+		QFile::remove(runnableJar.filePath());
+		emitFailed("Failed to open the minecraft.jar for stripping");
+		return;
+	}
+	// Modify the jar
+	setStatus(tr("Creating stripped jar: Adding files..."));
+	if (!MergeZipFiles(&zipOut, origPath))
+	{
+		zipOut.close();
+		QFile::remove(runnableJar.filePath());
+		emitFailed("Failed to add " + origPath + " to the jar.");
+		return;
+	}
+}
+
+bool OneSixUpdate::MergeZipFiles(QuaZip *into, QString from)
+{
+	setStatus(tr("Installing mods: Adding ") + from + " ...");
+
+	QuaZip modZip(from);
+	modZip.open(QuaZip::mdUnzip);
+
+	QuaZipFile fileInsideMod(&modZip);
+	QuaZipFile zipOutFile(into);
+	for (bool more = modZip.goToFirstFile(); more; more = modZip.goToNextFile())
+	{
+		QString filename = modZip.getCurrentFileName();
+		if (filename.contains("META-INF"))
+		{
+			QLOG_INFO() << "Skipping META-INF " << filename << " from " << from;
+			continue;
+		}
+		QLOG_INFO() << "Adding file " << filename << " from " << from;
+
+		if (!fileInsideMod.open(QIODevice::ReadOnly))
+		{
+			QLOG_ERROR() << "Failed to open " << filename << " from " << from;
+			return false;
+		}
+		/*
+		QuaZipFileInfo old_info;
+		fileInsideMod.getFileInfo(&old_info);
+		*/
+		QuaZipNewInfo info_out(fileInsideMod.getActualFileName());
+		/*
+		info_out.externalAttr = old_info.externalAttr;
+		*/
+		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;
+}
+
+
+void OneSixUpdate::fmllibsStart()
+{
+	// Get the mod list
+	OneSixInstance *inst = (OneSixInstance *)m_inst;
+	std::shared_ptr<VersionFinal> fullversion = inst->getFullVersion();
+	bool forge_present = false;
+
+	QString version = inst->intendedVersionId();
+	auto & fmlLibsMapping = g_VersionFilterData.fmlLibsMapping;
+	if (!fmlLibsMapping.contains(version))
+	{
+		assetIndexStart();
+		return;
+	}
+
+	auto &libList = fmlLibsMapping[version];
+
+	// determine if we need some libs for FML or forge
+	setStatus(tr("Checking for FML libraries..."));
+	forge_present = (fullversion->versionFile("net.minecraftforge") != nullptr);
+	// we don't...
+	if (!forge_present)
+	{
+		assetIndexStart();
+		return;
+	}
+
+	// now check the lib folder inside the instance for files.
+	for (auto &lib : libList)
+	{
+		QFileInfo libInfo(PathCombine(inst->libDir(), lib.filename));
+		if (libInfo.exists())
+			continue;
+		fmlLibsToProcess.append(lib);
+	}
+
+	// if everything is in place, there's nothing to do here...
+	if (fmlLibsToProcess.isEmpty())
+	{
+		assetIndexStart();
+		return;
+	}
+
+	// download missing libs to our place
+	setStatus(tr("Dowloading FML libraries..."));
+	auto dljob = new NetJob("FML libraries");
+	auto metacache = MMC->metacache();
+	for (auto &lib : fmlLibsToProcess)
+	{
+		auto entry = metacache->resolveEntry("fmllibs", lib.filename);
+		QString urlString = lib.ours ? URLConstants::FMLLIBS_OUR_BASE_URL + lib.filename
+									 : URLConstants::FMLLIBS_FORGE_BASE_URL + lib.filename;
+		dljob->addNetAction(CacheDownload::make(QUrl(urlString), entry));
+	}
+
+	connect(dljob, SIGNAL(succeeded()), SLOT(fmllibsFinished()));
+	connect(dljob, SIGNAL(failed()), SLOT(fmllibsFailed()));
+	connect(dljob, SIGNAL(progress(qint64, qint64)), SIGNAL(progress(qint64, qint64)));
+	legacyDownloadJob.reset(dljob);
+	legacyDownloadJob->start();
+}
+
+void OneSixUpdate::fmllibsFinished()
+{
+	legacyDownloadJob.reset();
+	if(!fmlLibsToProcess.isEmpty())
+	{
+		setStatus(tr("Copying FML libraries into the instance..."));
+		OneSixInstance *inst = (OneSixInstance *)m_inst;
+		auto metacache = MMC->metacache();
+		int index = 0;
+		for (auto &lib : fmlLibsToProcess)
+		{
+			progress(index, fmlLibsToProcess.size());
+			auto entry = metacache->resolveEntry("fmllibs", lib.filename);
+			auto path = PathCombine(inst->libDir(), lib.filename);
+			if(!ensureFilePathExists(path))
+			{
+				emitFailed(tr("Failed creating FML library folder inside the instance."));
+				return;
+			}
+			if (!QFile::copy(entry->getFullPath(), PathCombine(inst->libDir(), lib.filename)))
+			{
+				emitFailed(tr("Failed copying Forge/FML library: %1.").arg(lib.filename));
+				return;
+			}
+			index++;
+		}
+		progress(index, fmlLibsToProcess.size());
+	}
+	assetIndexStart();
+}
+
+void OneSixUpdate::fmllibsFailed()
+{
+	emitFailed("Game update failed: it was impossible to fetch the required FML libraries.");
+	return;
+}
\ No newline at end of file
diff --git a/logic/OneSixUpdate.h b/logic/OneSixUpdate.h
index eac882b5..00f7c135 100644
--- a/logic/OneSixUpdate.h
+++ b/logic/OneSixUpdate.h
@@ -21,6 +21,8 @@
 
 #include "logic/net/NetJob.h"
 #include "logic/tasks/Task.h"
+#include "logic/VersionFilterData.h"
+#include <quazip.h>
 
 class MinecraftVersion;
 class OneSixInstance;
@@ -42,6 +44,10 @@ slots:
 	void jarlibFinished();
 	void jarlibFailed();
 
+	void fmllibsStart();
+	void fmllibsFinished();
+	void fmllibsFailed();
+
 	void assetIndexStart();
 	void assetIndexFinished();
 	void assetIndexFailed();
@@ -49,11 +55,16 @@ slots:
 	void assetsFinished();
 	void assetsFailed();
 
+	void stripJar(QString origPath, QString newPath);
+	bool MergeZipFiles(QuaZip *into, QString from);
 private:
 	NetJobPtr specificVersionDownloadJob;
 	NetJobPtr jarlibDownloadJob;
+	NetJobPtr legacyDownloadJob;
 
 	// target version, determined during this task
 	std::shared_ptr<MinecraftVersion> targetVersion;
 	OneSixInstance *m_inst = nullptr;
+	QString jarHashOnEntry;
+	QList<FMLlib> fmlLibsToProcess;
 };
diff --git a/logic/URNResolver.cpp b/logic/URNResolver.cpp
new file mode 100644
index 00000000..b6bdcf41
--- /dev/null
+++ b/logic/URNResolver.cpp
@@ -0,0 +1,98 @@
+#include "URNResolver.h"
+#include <logger/Qs