fix import torrent with "Keep incomplete torrents in:" ticked

* also had to account for "Append the label of the torrent to the save path",
  but again, this was only an issue when "Keep incomplete torrents in:" is
  selected

* A multi-file torrent with only one file (ie: a single file within a folder),
  was being treated as a single-file torrent, making it impossible to import.
  Multi-file torrent detection code was copied from libtorrent.  The
  information is available in libtorrent (under torrent_info::m_multifile),
  however it's a private member and I chose to go with copying the code that
  determines it, rather than modifying a library qBittorrent depends on.

src/qtlibtorrent/qbtsession.cpp

@@ -1032,7 +1032,7 @@ QTorrentHandle QBtSession::addMagnetUri(QString magnet_uri, bool resumed, bool f
 }
 
 // Add a torrent to the Bittorrent session
-QTorrentHandle QBtSession::addTorrent(QString path, bool fromScanDir, QString from_url, bool resumed) {
+QTorrentHandle QBtSession::addTorrent(QString path, bool fromScanDir, QString from_url, bool resumed, bool imported) {
   QTorrentHandle h;
   Preferences pref;
 
@@ -1166,9 +1166,9 @@ QTorrentHandle QBtSession::addTorrent(QString path, bool fromScanDir, QString fr
     // Remember label
     TorrentTempData::setLabel(hash, savePath_label.second);
   } else {
-    savePath = getSavePath(hash, fromScanDir, path);
+    savePath = getSavePath(hash, fromScanDir, path, imported);
   }
-  if (!defaultTempPath.isEmpty() && !TorrentPersistentData::isSeed(hash)) {
+  if (!imported && !defaultTempPath.isEmpty() && !TorrentPersistentData::isSeed(hash)) {
     qDebug("addTorrent::Temp folder is enabled.");
     QString torrent_tmp_path = defaultTempPath.replace("\\", "/");
     p.save_path = torrent_tmp_path.toUtf8().constData();
@@ -2668,14 +2668,14 @@ session_status QBtSession::getSessionStatus() const {
   return s->status();
 }
 
-QString QBtSession::getSavePath(const QString &hash, bool fromScanDir, QString filePath) {
+QString QBtSession::getSavePath(const QString &hash, bool fromScanDir, QString filePath, bool imported) {
   QString savePath;
   if (TorrentTempData::hasTempData(hash)) {
     savePath = TorrentTempData::getSavePath(hash);
     if (savePath.isEmpty()) {
       savePath = defaultSavePath;
     }
-    if (appendLabelToSavePath) {
+    if (!imported && appendLabelToSavePath) {
       qDebug("appendLabelToSavePath is true");
       const QString label = TorrentTempData::getLabel(hash);
       if (!label.isEmpty()) {

src/qtlibtorrent/qbtsession.h

@@ -111,7 +111,7 @@ public:
   quint64 getAlltimeUL() const;
 
 public slots:
-  QTorrentHandle addTorrent(QString path, bool fromScanDir = false, QString from_url = QString(), bool resumed = false);
+  QTorrentHandle addTorrent(QString path, bool fromScanDir = false, QString from_url = QString(), bool resumed = false, bool imported = false);
   QTorrentHandle addMagnetUri(QString magnet_uri, bool resumed=false, bool fromScanDir=false, const QString &filePath=QString());
   void loadSessionState();
   void saveSessionState();
@@ -180,7 +180,7 @@ public slots:
   void unhideMagnet(const QString &hash);
 
 private:
-  QString getSavePath(const QString &hash, bool fromScanDir = false, QString filePath = QString::null);
+  QString getSavePath(const QString &hash, bool fromScanDir = false, QString filePath = QString::null, bool imported = false);
   bool loadFastResumeData(const QString &hash, std::vector<char> &buf);
   void loadTorrentSettings(QTorrentHandle &h);
   void loadTorrentTempData(QTorrentHandle &h, QString savePath, bool magnet);

src/torrentimportdlg.cpp

@@ -77,7 +77,16 @@ void TorrentImportDlg::on_browseContentBtn_clicked()
 {
   QIniSettings settings;
   const QString default_dir = settings.value(QString::fromUtf8("TorrentImport/LastContentDir"), QDir::homePath()).toString();
-  if (t->num_files() == 1) {
+  // Test for multi-file taken from libtorrent/create_torrent.hpp -> create_torrent::create_torrent
+  bool multifile = t->num_files() > 1;
+#if LIBTORRENT_VERSION_NUM >= 1600
+  if (!multifile && has_parent_path(t->files().file_path(*(t->files().begin()))))
+      multifile = true;
+#else
+  if (!multifile && t->file_at(0).path.has_parent_path())
+      multifile = true;
+#endif
+  if (!multifile) {
     // Single file torrent
 #if LIBTORRENT_VERSION_NUM >= 1600
     const QString file_name = fsutils::fileName(misc::toQStringU(t->file_at(0).path));
@@ -211,7 +220,7 @@ void TorrentImportDlg::importTorrent()
     TorrentTempData::setSavePath(hash, content_path);
     TorrentTempData::setSeedingMode(hash, dlg.skipFileChecking());
     qDebug("Adding the torrent to the session...");
-    QBtSession::instance()->addTorrent(torrent_path);
+    QBtSession::instance()->addTorrent(torrent_path, false, QString(), false, true);
     // Remember the last opened folder
     QIniSettings settings;
     settings.setValue(QString::fromUtf8("MainWindowLastDir"), torrent_path);