BUGFIX: Do not allocate space for unwanted files (preallocation mode)

Changelog

@@ -12,6 +12,7 @@
     - FEATURE: Added a search engine plugin for kickasstorrents.com
     - FEATURE: Added auto-suspend upon downloads completion feature
     - BUGFIX: Hide unwanted files that have to be partly downloaded
+    - BUGFIX: Do not allocate space for unwanted files (preallocation mode)
     - I18N: Added Galician translation
     - COSMETIC: Same deletion confirmation dialog in the GUI and Web UI
     - COSMETIC: Simplified the top toolbar

src/qtlibtorrent/qbtsession.cpp

@@ -932,7 +932,20 @@ QTorrentHandle QBtSession::addTorrent(QString path, bool fromScanDir, QString fr
       p.resume_data = &buf;
       qDebug("Successfully loaded fast resume data");
     }
+  } else {
+    // Generate fake resume data to make sure unwanted files
+    // are not allocated
+    if(preAllocateAll) {
+      vector<int> fp;
+      TorrentTempData::getFilesPriority(hash, fp);
+      if((int)fp.size() == t->num_files()) {
+        entry rd = generateFilePriorityResumeData(t, fp);
+        bencode(std::back_inserter(buf), rd);
+        p.resume_data = &buf;
+      }
     }
+  }
+
   QString savePath;
   if(!from_url.isEmpty() && savepathLabel_fromurl.contains(QUrl::fromEncoded(from_url.toLocal8Bit()))) {
     // Enforcing the save path defined before URL download (from RSS for example)
@@ -2567,3 +2580,45 @@ void QBtSession::handleIPFilterError()
   addConsoleMessage(tr("Error: Failed to parse the provided IP filter."), "red");
   emit ipFilterParsed(true, 0);
 }
+
+entry QBtSession::generateFilePriorityResumeData(boost::intrusive_ptr<torrent_info> t, const std::vector<int> &fp)
+{
+  entry::dictionary_type rd;
+  rd["file-format"] = "libtorrent resume file";
+  rd["file-version"] = 1;
+  rd["libtorrent-version"] = LIBTORRENT_VERSION;
+  rd["allocation"] = "full";
+  sha1_hash info_hash = t->info_hash();
+  rd["info-hash"] = std::string((char*)info_hash.begin(), (char*)info_hash.end());
+  // Priorities
+  entry::list_type priorities;
+  priorities.resize(fp.size());
+  for(uint i=0; i<fp.size(); ++i) {
+    priorities.push_back(entry(fp[i]));
+  }
+  rd["file_priority"] = entry(priorities);
+  // files sizes (useless but required)
+  entry::list_type sizes;
+  for(int i=0; i<t->num_files(); ++i) {
+    entry::list_type p;
+    p.push_back(entry(0));
+    p.push_back(entry(0));
+    sizes.push_back(entry(p));
+  }
+  rd["file sizes"] = entry(sizes);
+  // Slots
+  entry::list_type tslots;
+
+  for(int i=0; i<t->num_pieces(); ++i) {
+    tslots.push_back(-1);
+  }
+  rd["slots"] = entry(tslots);
+
+  entry::string_type pieces;
+  std::memset(&pieces[0], 0, t->num_pieces());
+  rd["pieces"] = entry(pieces);
+
+  entry ret(rd);
+  Q_ASSERT(ret.type() == entry::dictionary_t);
+  return ret;
+}

src/qtlibtorrent/qbtsession.h

@@ -167,6 +167,7 @@ private:
   void loadTorrentSettings(QTorrentHandle h);
   void loadTorrentTempData(QTorrentHandle h, QString savePath, bool magnet);
   libtorrent::add_torrent_params initializeAddTorrentParams(QString hash);
+  libtorrent::entry generateFilePriorityResumeData(boost::intrusive_ptr<libtorrent::torrent_info> t, const std::vector<int> &fp);
 
 private slots:
   void addTorrentsFromScanFolder(QStringList&);

src/qtlibtorrent/qtorrenthandle.cpp

@@ -500,15 +500,14 @@ void QTorrentHandle::file_priority(int index, int priority) const {
   }
 }
 
-// TODO: Also hide the folder on Windows
 void QTorrentHandle::prioritize_files(const vector<int> &files) const {
   if((int)files.size() != torrent_handle::get_torrent_info().num_files()) return;
-  const vector<int> prev_priorities = torrent_handle::file_priorities();
+  qDebug() << Q_FUNC_INFO;
   bool was_seed = is_seed();
   torrent_handle::prioritize_files(files);
   for(uint i=0; i<files.size(); ++i) {
     // Move unwanted files to a .unwanted subfolder
-    if(prev_priorities[i] > 0 && files[i] == 0) {
+    if(files[i] == 0) {
       QString old_path = filepath_at(i);
       QString old_name = filename_at(i);
       QString parent_path = misc::branchPath(old_path);
@@ -535,7 +534,7 @@ void QTorrentHandle::prioritize_files(const vector<int> &files) const {
       }
     }
     // Move wanted files back to their original folder
-    if(prev_priorities[i] == 0 && files[i] > 0) {
+    if(files[i] > 0) {
       QString old_path = filepath_at(i);
       QString old_name = filename_at(i);
       QDir parent_path(misc::branchPath(old_path));