From 0c6c65f6f89b5d67a52ff23d7c399560a568db50 Mon Sep 17 00:00:00 2001
From: "Vladimir Golovnev (Glassez)" <glassez@yandex.ru>
Date: Thu, 9 Jan 2020 14:35:25 +0300
Subject: [PATCH] Keep legacy defaults for existing users

---
 src/app/main.cpp    |  6 ++++++
 src/app/upgrade.cpp | 20 ++++++++++++++++++++
 src/app/upgrade.h   |  7 +++++++
 3 files changed, 33 insertions(+)

diff --git a/src/app/main.cpp b/src/app/main.cpp
index 1fffae4da..2a9f84862 100644
--- a/src/app/main.cpp
+++ b/src/app/main.cpp
@@ -237,6 +237,8 @@ int main(int argc, char *argv[])
 #endif
 
         if (!firstTimeUser) {
+            handleChangedDefaults(DefaultPreferencesMode::Legacy);
+
 #ifndef DISABLE_GUI
             if (!upgrade()) return EXIT_FAILURE;
 #elif defined(Q_OS_WIN)
@@ -248,6 +250,10 @@ int main(int argc, char *argv[])
                          && isatty(fileno(stdout)))) return EXIT_FAILURE;
 #endif
         }
+        else {
+            handleChangedDefaults(DefaultPreferencesMode::Current);
+        }
+
 #if defined(DISABLE_GUI) && !defined(Q_OS_WIN)
         if (params.shouldDaemonize) {
             app.reset(); // Destroy current application
diff --git a/src/app/upgrade.cpp b/src/app/upgrade.cpp
index 99bcde1a0..e0a1060cc 100644
--- a/src/app/upgrade.cpp
+++ b/src/app/upgrade.cpp
@@ -82,3 +82,23 @@ bool upgrade(const bool /*ask*/)
     exportWebUIHttpsFiles();
     return true;
 }
+
+void handleChangedDefaults(const DefaultPreferencesMode mode)
+{
+    struct DefaultValue
+    {
+        QString name;
+        QVariant legacy;
+        QVariant current;
+    };
+
+    const QVector<DefaultValue> changedDefaults {
+        {QLatin1String {"BitTorrent/Session/QueueingSystemEnabled"}, true, false}
+    };
+
+    SettingsStorage *settingsStorage {SettingsStorage::instance()};
+    for (auto it = changedDefaults.cbegin(); it != changedDefaults.cend(); ++it) {
+        if (settingsStorage->loadValue(it->name).isNull())
+            settingsStorage->storeValue(it->name, (mode == DefaultPreferencesMode::Legacy ? it->legacy : it->current));
+    }
+}
diff --git a/src/app/upgrade.h b/src/app/upgrade.h
index 28c336fd2..62bea4c42 100644
--- a/src/app/upgrade.h
+++ b/src/app/upgrade.h
@@ -28,4 +28,11 @@
 
 #pragma once
 
+enum class DefaultPreferencesMode
+{
+    Legacy,
+    Current
+};
+
+void handleChangedDefaults(DefaultPreferencesMode mode);
 bool upgrade(bool ask = true);