From c33b4e252f8bf37bc716adc7789926185c3e384c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Petr=20Mr=C3=A1zek?= <peterix@gmail.com>
Date: Sun, 21 Jan 2018 03:49:54 +0100
Subject: [PATCH] NOISSUE fix bad redirect URLs provided by the curse CDN

MultiMC now parses the HTTP Location header in a (more) tolerant mode.
---
 api/logic/InstanceImportTask.cpp              |  1 +
 .../minecraft/flame/FileResolvingTask.cpp     |  8 +++-
 api/logic/minecraft/flame/PackManifest.h      |  3 +-
 api/logic/net/Download.cpp                    | 42 ++++++++++++++++++-
 4 files changed, 50 insertions(+), 4 deletions(-)

diff --git a/api/logic/InstanceImportTask.cpp b/api/logic/InstanceImportTask.cpp
index 046f885d..2b481300 100644
--- a/api/logic/InstanceImportTask.cpp
+++ b/api/logic/InstanceImportTask.cpp
@@ -327,6 +327,7 @@ void InstanceImportTask::processFlame()
 				case Flame::File::Type::SingleFile:
 				case Flame::File::Type::Mod:
 				{
+					qDebug() << "Will download" << result.url << "to" << path;
 					auto dl = Net::Download::makeFile(result.url, path);
 					m_filesNetJob->addNetAction(dl);
 					break;
diff --git a/api/logic/minecraft/flame/FileResolvingTask.cpp b/api/logic/minecraft/flame/FileResolvingTask.cpp
index af8ef7aa..980b8c3a 100644
--- a/api/logic/minecraft/flame/FileResolvingTask.cpp
+++ b/api/logic/minecraft/flame/FileResolvingTask.cpp
@@ -48,7 +48,13 @@ void Flame::FileResolvingTask::netJobFinished()
 				continue;
 			}
 			out.fileName = Json::requireString(obj, "FileNameOnDisk");
-			out.url = Json::requireString(obj, "DownloadURL");
+			auto urlString = Json::requireString(obj, "DownloadURL");
+			urlString.replace(' ', "%20");
+			out.url = QUrl(urlString, QUrl::StrictMode);
+			if(!out.url.isValid())
+			{
+				throw "Perkele!";
+			}
 			// This is a piece of a Flame project JSON pulled out into the file metadata (here) for convenience
 			// It is also optional
 			QJsonObject projObj = Json::ensureObject(obj, "_Project", {});
diff --git a/api/logic/minecraft/flame/PackManifest.h b/api/logic/minecraft/flame/PackManifest.h
index 07bf92b6..1a5254a8 100644
--- a/api/logic/minecraft/flame/PackManifest.h
+++ b/api/logic/minecraft/flame/PackManifest.h
@@ -2,6 +2,7 @@
 
 #include <QString>
 #include <QVector>
+#include <QUrl>
 
 namespace Flame
 {
@@ -15,7 +16,7 @@ struct File
 	// our
 	bool resolved = false;
 	QString fileName;
-	QString url;
+	QUrl url;
 	QString targetFolder = QLatin1Literal("mods");
 	enum class Type
 	{
diff --git a/api/logic/net/Download.cpp b/api/logic/net/Download.cpp
index 816d2002..e45c41cb 100644
--- a/api/logic/net/Download.cpp
+++ b/api/logic/net/Download.cpp
@@ -150,13 +150,50 @@ void Download::sslErrors(const QList<QSslError> & errors)
 
 bool Download::handleRedirect()
 {
-	QVariant redirect = m_reply->header(QNetworkRequest::LocationHeader);
+	QUrl redirect = m_reply->header(QNetworkRequest::LocationHeader).toUrl();
+	if(!redirect.isValid())
+	{
+		if(!m_reply->hasRawHeader("Location"))
+		{
+			// no redirect -> it's fine to continue
+			return false;
+		}
+		// there is a Location header, but it's not correct. we need to apply some workarounds...
+		QByteArray redirectBA = m_reply->rawHeader("Location");
+		if(redirectBA.size() == 0)
+		{
+			// empty, yet present redirect header? WTF?
+			return false;
+		}
+		QString redirectStr = QString::fromUtf8(redirectBA);
+
+		/*
+		 * IF the URL begins with //, we need to insert the URL scheme.
+		 * See: https://bugreports.qt-project.org/browse/QTBUG-41061
+		 */
+		if(redirectStr.startsWith("//"))
+		{
+			redirectStr = m_reply->url().scheme() + ":" + redirectStr;
+		}
+
+		/*
+		 * Next, make sure the URL is parsed in tolerant mode. Qt doesn't parse the location header in tolerant mode, which causes issues.
+		 * FIXME: report Qt bug for this
+		 */
+		redirect = QUrl(redirectStr, QUrl::TolerantMode);
+		qDebug() << "Fixed location header:" << redirect;
+	}
+	else
+	{
+		qDebug() << "Location header:" << redirect;
+	}
+
 	QString redirectURL;
 	if(redirect.isValid())
 	{
 		redirectURL = redirect.toString();
 	}
-	// FIXME: This is a hack for https://bugreports.qt-project.org/browse/QTBUG-41061
+	// FIXME: This is a hack for
 	else if(m_reply->hasRawHeader("Location"))
 	{
 		auto data = m_reply->rawHeader("Location");
@@ -165,6 +202,7 @@ bool Download::handleRedirect()
 			redirectURL = m_reply->url().scheme() + ":" + data;
 		}
 	}
+
 	if (!redirectURL.isEmpty())
 	{
 		m_url = QUrl(redirect.toString());