Fix label filter. Closes #3429.

src/core/torrentfilter.cpp

@@ -107,7 +107,10 @@ bool TorrentFilter::setHashSet(const QStringSet &hashSet)
 
 bool TorrentFilter::setLabel(const QString &label)
 {
-    if (m_label != label) {
+    // QString::operator==() doesn't distinguish between empty and null strings.
+    if ((m_label != label)
+            || (m_label.isNull() && !label.isNull())
+            || (!m_label.isNull() && label.isNull())) {
         m_label = label;
         return true;
     }
@@ -154,6 +157,7 @@ bool TorrentFilter::matchHash(BitTorrent::TorrentHandle *const torrent) const
 
 bool TorrentFilter::matchLabel(BitTorrent::TorrentHandle *const torrent) const
 {
-    if (m_label == AnyLabel) return true;
+    if (m_label.isNull()) return true;
+    else if (m_label.isEmpty()) return torrent->label().isEmpty();
     else return (torrent->label() == m_label);
 }

src/gui/transferlistfilterswidget.cpp

@@ -375,16 +375,7 @@ void LabelFiltersList::showMenu(QPoint)
 
 void LabelFiltersList::applyFilter(int row)
 {
-    switch (row) {
-    case 0:
-        transferList->applyLabelFilterAll();
-        break;
-    case 1:
-        transferList->applyLabelFilter(QString());
-        break;
-    default:
-        transferList->applyLabelFilter(labelFromRow(row));
-    }
+    transferList->applyLabelFilter(labelFromRow(row));
 }
 
 void LabelFiltersList::handleNewTorrent(BitTorrent::TorrentHandle *const torrent)
@@ -407,7 +398,9 @@ void LabelFiltersList::torrentAboutToBeDeleted(BitTorrent::TorrentHandle *const
 
 QString LabelFiltersList::labelFromRow(int row) const
 {
-    Q_ASSERT(row > 1);
+    if (row == 0) return QString(); // All
+    if (row == 1) return QLatin1String(""); // Unlabeled
+
     const QString &label = item(row)->text();
     QStringList parts = label.split(" ");
     Q_ASSERT(parts.size() >= 2);

src/gui/transferlistwidget.cpp

@@ -843,15 +843,12 @@ void TransferListWidget::currentChanged(const QModelIndex& current, const QModel
     emit currentTorrentChanged(torrent);
 }
 
-void TransferListWidget::applyLabelFilterAll()
-{
-    nameFilterModel->disableLabelFilter();
-}
-
 void TransferListWidget::applyLabelFilter(QString label)
 {
-    qDebug("Applying Label filter: %s", qPrintable(label));
-    nameFilterModel->setLabelFilter(label);
+    if (label.isNull())
+        nameFilterModel->disableLabelFilter();
+    else
+        nameFilterModel->setLabelFilter(label);
 }
 
 void TransferListWidget::applyTrackerFilterAll()

src/gui/transferlistwidget.h

@@ -86,7 +86,6 @@ public slots:
     void displayDLHoSMenu(const QPoint&);
     void applyNameFilter(const QString& name);
     void applyStatusFilter(int f);
-    void applyLabelFilterAll();
     void applyLabelFilter(QString label);
     void applyTrackerFilterAll();
     void applyTrackerFilter(const QStringList &hashes);