fix corruption: torrentVerify on completion (#4178)

* torrentVerify on completion

* Make torrent verify on completion configurable via settings

* code review: replacing tr_verify_complete_mode with bool

* code review: sorting torrent_complete_verify_enabled with bool

* Update Application.cc

* code review: avoiding `session->onTorrentCompletenessChanged` before verification completion

libtransmission/quark.cc

@@ -386,6 +386,7 @@ auto constexpr MyStatic = std::array<std::string_view, TR_N_KEYS>{
     "torrent-complete-notification-enabled"sv,
     "torrent-complete-sound-command"sv,
     "torrent-complete-sound-enabled"sv,
+    "torrent-complete-verify-enabled"sv,
     "torrent-duplicate"sv,
     "torrent-get"sv,
     "torrent-set"sv,

libtransmission/quark.h

@@ -388,6 +388,7 @@ enum // NOLINT(performance-enum-size)
     TR_KEY_torrent_complete_notification_enabled,
     TR_KEY_torrent_complete_sound_command,
     TR_KEY_torrent_complete_sound_enabled,
+    TR_KEY_torrent_complete_verify_enabled,
     TR_KEY_torrent_duplicate,
     TR_KEY_torrent_get,
     TR_KEY_torrent_set,

libtransmission/session.cc

@@ -1659,6 +1659,15 @@ size_t tr_sessionGetCacheLimit_MB(tr_session const* session)
 
 // ---
 
+void tr_sessionSetCompleteVerifyEnabled(tr_session* session, bool enabled)
+{
+    TR_ASSERT(session != nullptr);
+
+    session->settings_.torrent_complete_verify_enabled = enabled;
+}
+
+// ---
+
 void tr_session::setDefaultTrackers(std::string_view trackers)
 {
     auto const oldval = default_trackers_;

libtransmission/session.h

@@ -416,6 +416,7 @@ public:
         bool speed_limit_down_enabled = false;
         bool speed_limit_up_enabled = false;
         bool tcp_enabled = true;
+        bool torrent_complete_verify_enabled = false;
         bool utp_enabled = true;
         double ratio_limit = 2.0;
         size_t cache_size_mbytes = 4U;
@@ -513,6 +514,7 @@ public:
                 { TR_KEY_start_added_torrents, &should_start_added_torrents },
                 { TR_KEY_tcp_enabled, &tcp_enabled },
                 { TR_KEY_torrent_added_verify_mode, &torrent_added_verify_mode },
+                { TR_KEY_torrent_complete_verify_enabled, &torrent_complete_verify_enabled },
                 { TR_KEY_trash_original_torrent_files, &should_delete_source_torrents },
                 { TR_KEY_umask, &umask },
                 { TR_KEY_upload_slots_per_torrent, &upload_slots_per_torrent },
@@ -963,6 +965,11 @@ public:
         return settings().torrent_added_verify_mode == TR_VERIFY_ADDED_FULL;
     }
 
+    [[nodiscard]] constexpr auto shouldFullyVerifyCompleteTorrents() const noexcept
+    {
+        return settings().torrent_complete_verify_enabled;
+    }
+
     [[nodiscard]] constexpr auto shouldDeleteSource() const noexcept
     {
         return settings().should_delete_source_torrents;
@@ -1207,6 +1214,7 @@ private:
     friend void tr_sessionSetAntiBruteForceEnabled(tr_session* session, bool is_enabled);
     friend void tr_sessionSetAntiBruteForceThreshold(tr_session* session, int max_bad_requests);
     friend void tr_sessionSetCacheLimit_MB(tr_session* session, size_t mbytes);
+    friend void tr_sessionSetCompleteVerifyEnabled(tr_session* session, bool enabled);
     friend void tr_sessionSetDHTEnabled(tr_session* session, bool enabled);
     friend void tr_sessionSetDeleteSource(tr_session* session, bool delete_source);
     friend void tr_sessionSetEncryption(tr_session* session, tr_encryption_mode mode);

libtransmission/torrent.cc

@@ -1786,6 +1786,12 @@ void tr_torrent::recheck_completeness()
         bool const recent_change = bytes_downloaded_.during_this_session() != 0U;
         bool const was_running = is_running();
 
+        if (new_completeness != TR_LEECH && was_running && session->shouldFullyVerifyCompleteTorrents())
+        {
+            tr_torrentVerify(this);
+            return;
+        }
+
         tr_logAddTraceTor(
             this,
             fmt::format(
@@ -1794,10 +1800,11 @@ void tr_torrent::recheck_completeness()
                 get_completion_string(new_completeness)));
 
         completeness_ = new_completeness;
-        session->close_torrent_files(id());
 
         if (is_done())
         {
+            session->close_torrent_files(id());
+
             if (recent_change)
             {
                 // https://www.bittorrent.org/beps/bep_0003.html

libtransmission/transmission.h

@@ -635,7 +635,7 @@ size_t tr_sessionGetQueueStalledMinutes(tr_session const* session);
     Stalled torrents are left running but are not counted by `tr_sessionGetQueueSize()`. */
 void tr_sessionSetQueueStalledMinutes(tr_session* session, int minutes);
 
-/** @return true if we're torrents idle for over N minutes will be flagged as 'stalled' */
+/** @return true if torrents idle for over N minutes will be flagged as 'stalled' */
 bool tr_sessionGetQueueStalledEnabled(tr_session const* session);
 
 /** @brief Set whether or not to count torrents idle for over N minutes as 'stalled' */
@@ -646,10 +646,14 @@ void tr_sessionSetQueueStartCallback(tr_session* session, void (*callback)(tr_se
 
 // ---
 
+/** @brief Set whether or not to verify data when torrent download is complete */
+void tr_sessionSetCompleteVerifyEnabled(tr_session* session, bool enabled);
+
+// ---
+
 /**
  * Load all the torrents in the session's torrent folder.
- * This can be used at startup to kickstart all the torrents
- * from the previous session.
+ * This can be used at startup to kickstart all the torrents from the previous session.
  *
  * @return the number of torrents in the session
  */