Always honor the configured behavior for merging trackers

PR #19305.

* Always honor the configured behavior for merging trackers
* Clarify merging trackers related options

src/base/bittorrent/sessionimpl.cpp

@@ -2747,10 +2747,16 @@ bool SessionImpl::addTorrent_impl(const std::variant<MagnetUri, TorrentInfo> &so
             torrent->setMetadata(std::get<TorrentInfo>(source));
         }
 
+        if (!isMergeTrackersEnabled())
+        {
+            LogMsg(tr("Detected an attempt to add a duplicate torrent. Merging of trackers is disabled. Torrent: %1").arg(torrent->name()));
+            return false;
+        }
+
         const bool isPrivate = torrent->isPrivate() || (hasMetadata && std::get<TorrentInfo>(source).isPrivate());
         if (isPrivate)
         {
-            LogMsg(tr("Found existing torrent. Trackers cannot be merged because it is a private torrent. Torrent: %1").arg(torrent->name()));
+            LogMsg(tr("Detected an attempt to add a duplicate torrent. Trackers cannot be merged because it is a private torrent. Torrent: %1").arg(torrent->name()));
             return false;
         }
 
@@ -2771,7 +2777,7 @@ bool SessionImpl::addTorrent_impl(const std::variant<MagnetUri, TorrentInfo> &so
             torrent->addUrlSeeds(magnetUri.urlSeeds());
         }
 
-        LogMsg(tr("Found existing torrent. Trackers are merged from new source. Torrent: %1").arg(torrent->name()));
+        LogMsg(tr("Detected an attempt to add a duplicate torrent. Trackers are merged from new source. Torrent: %1").arg(torrent->name()));
         return false;
     }
 

src/gui/optionsdialog.cpp

@@ -505,7 +505,13 @@ void OptionsDialog::loadDownloadsTabOptions()
     m_ui->stopConditionComboBox->setEnabled(!m_ui->checkStartPaused->isChecked());
 
     m_ui->checkMergeTrackers->setChecked(session->isMergeTrackersEnabled());
-    m_ui->checkConfirmMergeTrackers->setChecked(pref->confirmMergeTrackers());
+    m_ui->checkConfirmMergeTrackers->setEnabled(m_ui->checkAdditionDialog->isChecked());
+    m_ui->checkConfirmMergeTrackers->setChecked(m_ui->checkConfirmMergeTrackers->isEnabled() ? pref->confirmMergeTrackers() : false);
+    connect(m_ui->checkAdditionDialog, &QGroupBox::toggled, this, [this, pref]
+    {
+        m_ui->checkConfirmMergeTrackers->setEnabled(m_ui->checkAdditionDialog->isChecked());
+        m_ui->checkConfirmMergeTrackers->setChecked(m_ui->checkConfirmMergeTrackers->isEnabled() ? pref->confirmMergeTrackers() : false);
+    });
 
     const TorrentFileGuard::AutoDeleteMode autoDeleteMode = TorrentFileGuard::autoDeleteMode();
     m_ui->deleteTorrentBox->setChecked(autoDeleteMode != TorrentFileGuard::Never);
@@ -692,7 +698,8 @@ void OptionsDialog::saveDownloadsTabOptions() const
                              : !m_ui->deleteCancelledTorrentBox->isChecked() ? TorrentFileGuard::IfAdded
                              : TorrentFileGuard::Always);
     session->setMergeTrackersEnabled(m_ui->checkMergeTrackers->isChecked());
-    pref->setConfirmMergeTrackers(m_ui->checkConfirmMergeTrackers->isChecked());
+    if (m_ui->checkConfirmMergeTrackers->isEnabled())
+        pref->setConfirmMergeTrackers(m_ui->checkConfirmMergeTrackers->isChecked());
 
     session->setPreallocationEnabled(preAllocateAllFiles());
     session->setAppendExtensionEnabled(m_ui->checkAppendqB->isChecked());

src/gui/optionsdialog.ui

@@ -958,9 +958,6 @@
                  <layout class="QVBoxLayout" name="duplicateTorrentBoxLayout">
                   <item>
                    <widget class="QCheckBox" name="checkMergeTrackers">
-                    <property name="toolTip">
-                     <string>Whether trackers should be merged to existing torrent</string>
-                    </property>
                     <property name="text">
                      <string>Merge trackers to existing torrent</string>
                     </property>
@@ -971,11 +968,8 @@
                   </item>
                   <item>
                    <widget class="QCheckBox" name="checkConfirmMergeTrackers">
-                    <property name="toolTip">
-                     <string>Shows a confirmation dialog upon merging trackers to existing torrent</string>
-                    </property>
                     <property name="text">
-                     <string>Confirm merging trackers</string>
+                     <string>Ask for merging trackers when torrent is being added manually</string>
                     </property>
                     <property name="checked">
                      <bool>true</bool>