From a84259dd1a6f1576c5049b4db75f70f1cf57292e Mon Sep 17 00:00:00 2001
From: Vladimir Golovnev <glassez@yandex.ru>
Date: Fri, 29 Sep 2023 07:33:19 +0300
Subject: [PATCH] Filter out duplicate trackers when replacing

PR #19656.
---
 src/base/bittorrent/torrentimpl.cpp | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/src/base/bittorrent/torrentimpl.cpp b/src/base/bittorrent/torrentimpl.cpp
index 8c6499a7c..f11256557 100644
--- a/src/base/bittorrent/torrentimpl.cpp
+++ b/src/base/bittorrent/torrentimpl.cpp
@@ -600,6 +600,9 @@ void TorrentImpl::replaceTrackers(QVector<TrackerEntry> trackers)
 {
     // TODO: use std::erase_if() in C++20
     trackers.erase(std::remove_if(trackers.begin(), trackers.end(), [](const TrackerEntry &entry) { return entry.url.isEmpty(); }), trackers.end());
+    // Filter out duplicate trackers
+    const auto uniqueTrackers = QSet<TrackerEntry>(trackers.cbegin(), trackers.cend());
+    trackers = QVector<TrackerEntry>(uniqueTrackers.cbegin(), uniqueTrackers.cend());
     std::sort(trackers.begin(), trackers.end()
         , [](const TrackerEntry &lhs, const TrackerEntry &rhs) { return lhs.tier < rhs.tier; });