SessionManager: Use relative paths for session files in settings

See #2331

src/lib/session/sessionmanager.cpp

@@ -310,11 +310,17 @@ void SessionManager::fillSessionsMetaDataListIfNeeded()
 
 void SessionManager::loadSettings()
 {
+    QDir sessionsDir(DataPaths::path(DataPaths::Sessions));
+
     Settings settings;
     settings.beginGroup("Web-Browser-Settings");
     m_lastActiveSessionPath = settings.value("lastActiveSessionPath", defaultSessionPath()).toString();
     settings.endGroup();
 
+    if (QDir::isRelativePath(m_lastActiveSessionPath)) {
+        m_lastActiveSessionPath = sessionsDir.absoluteFilePath(m_lastActiveSessionPath);
+    }
+
     // fallback to default session
     if (!QFile::exists(m_lastActiveSessionPath))
         m_lastActiveSessionPath = defaultSessionPath();
@@ -322,9 +328,11 @@ void SessionManager::loadSettings()
 
 void SessionManager::saveSettings()
 {
+    QDir sessionsDir(DataPaths::path(DataPaths::Sessions));
+
     Settings settings;
     settings.beginGroup("Web-Browser-Settings");
-    settings.setValue("lastActiveSessionPath", m_lastActiveSessionPath);
+    settings.setValue("lastActiveSessionPath", sessionsDir.relativeFilePath(m_lastActiveSessionPath));
     settings.endGroup();
 }