Suppress multiple I/O errors for the same torrent

When a file error happens libtorrent spews a ton of `file_error_alert`
which result in log floods and notification balloon floods. The later
might render the program inaccessible because the constant
notifications prevent the user from interacting with the tray icon.

Closes #8934

src/base/bittorrent/session.cpp

@@ -370,11 +370,16 @@ Session::Session(QObject *parent)
     , m_numResumeData(0)
     , m_extraLimit(0)
     , m_useProxy(false)
+    , m_recentErroredTorrentsTimer(new QTimer(this))
 {
     Logger *const logger = Logger::instance();
 
     initResumeFolder();
 
+    m_recentErroredTorrentsTimer->setSingleShot(true);
+    m_recentErroredTorrentsTimer->setInterval(1000);
+    connect(m_recentErroredTorrentsTimer, &QTimer::timeout, this, [this]() { m_recentErroredTorrents.clear(); });
+
     m_seedingLimitTimer = new QTimer(this);
     m_seedingLimitTimer->setInterval(10000);
     connect(m_seedingLimitTimer, &QTimer::timeout, this, &Session::processShareLimits);
@@ -4184,10 +4189,15 @@ void Session::handleFileErrorAlert(libt::file_error_alert *p)
     // NOTE: Check this function!
     TorrentHandle *const torrent = m_torrents.value(p->handle.info_hash());
     if (torrent) {
-        QString msg = QString::fromStdString(p->message());
-        Logger::instance()->addMessage(tr("An I/O error occurred, '%1' paused. %2")
-                           .arg(torrent->name(), msg));
-        emit fullDiskError(torrent, msg);
+        const InfoHash hash = torrent->hash();
+        if (!m_recentErroredTorrents.contains(hash)) {
+            m_recentErroredTorrents.insert(hash);
+            const QString msg = QString::fromStdString(p->message());
+            LogMsg(tr("An I/O error occurred, '%1' paused. %2").arg(torrent->name(), msg));
+            emit fullDiskError(torrent, msg);
+        }
+
+        m_recentErroredTorrentsTimer->start();
     }
 }
 

src/base/bittorrent/session.h

@@ -761,6 +761,10 @@ namespace BitTorrent
         QStringMap m_categories;
         QSet<QString> m_tags;
 
+        // I/O errored torrents
+        QSet<InfoHash> m_recentErroredTorrents;
+        QTimer *m_recentErroredTorrentsTimer;
+
 #if LIBTORRENT_VERSION_NUM < 10100
         QMutex m_alertsMutex;
         QWaitCondition m_alertsWaitCondition;