From 4b882b1bad9560985075273ec2900d7c22bcc77d Mon Sep 17 00:00:00 2001
From: Yat Ho <lagoho7@gmail.com>
Date: Sat, 16 Dec 2023 22:47:55 +0800
Subject: [PATCH] fix: sometimes stuck magnet metadata transfer (#6364)

* fix: don't check `total_size` against `metadata_size_hint`

* refactor: remove `metadata_size_hint`

* refactor: restart metadata transfer from scratch on failing
---
 libtransmission/peer-msgs.cc      | 10 ++++------
 libtransmission/torrent-magnet.cc | 21 +++++----------------
 2 files changed, 9 insertions(+), 22 deletions(-)

diff --git a/libtransmission/peer-msgs.cc b/libtransmission/peer-msgs.cc
index a7d1f44dc..bba95c46a 100644
--- a/libtransmission/peer-msgs.cc
+++ b/libtransmission/peer-msgs.cc
@@ -626,8 +626,6 @@ public:
 
     EncryptionPreference encryption_preference = EncryptionPreference::Unknown;
 
-    int64_t metadata_size_hint = 0;
-
     tr_torrent* const torrent;
 
     std::shared_ptr<tr_peerIo> const io;
@@ -1060,9 +1058,9 @@ void parseLtepHandshake(tr_peerMsgsImpl* msgs, MessageReader& payload)
     }
 
     /* look for metainfo size (BEP 9) */
-    if (tr_variantDictFindInt(&*var, TR_KEY_metadata_size, &i) && tr_torrentSetMetadataSizeHint(msgs->torrent, i))
+    if (tr_variantDictFindInt(&*var, TR_KEY_metadata_size, &i))
     {
-        msgs->metadata_size_hint = i;
+        tr_torrentSetMetadataSizeHint(msgs->torrent, i);
     }
 
     /* look for upload_only (BEP 21) */
@@ -1139,8 +1137,8 @@ void parseUtMetadata(tr_peerMsgsImpl* msgs, MessageReader& payload_in)
 
     auto const* const benc_end = serde.end();
 
-    if (msg_type == MetadataMsgType::Data && total_size == msgs->metadata_size_hint && !msgs->torrent->has_metainfo() &&
-        msg_end - benc_end <= MetadataPieceSize && piece * MetadataPieceSize + (msg_end - benc_end) <= total_size)
+    if (msg_type == MetadataMsgType::Data && !msgs->torrent->has_metainfo() && msg_end - benc_end <= MetadataPieceSize &&
+        piece * MetadataPieceSize + (msg_end - benc_end) <= total_size)
     {
         size_t const piece_len = msg_end - benc_end;
         tr_torrentSetMetadataPiece(msgs->torrent, piece, benc_end, piece_len);
diff --git a/libtransmission/torrent-magnet.cc b/libtransmission/torrent-magnet.cc
index 73318895b..bcf768bb9 100644
--- a/libtransmission/torrent-magnet.cc
+++ b/libtransmission/torrent-magnet.cc
@@ -263,27 +263,16 @@ void on_have_all_metainfo(tr_torrent* tor)
     auto error = tr_error{};
     auto& m = tor->incomplete_metadata;
     TR_ASSERT(m);
-    if (use_new_metainfo(tor, &error))
-    {
-        m.reset();
-    }
-    else /* drat. */
-    {
-        auto const n = m->piece_count;
-
-        m->pieces_needed = create_all_needed(n);
 
+    if (!use_new_metainfo(tor, &error)) /* drat. */
+    {
         auto msg = std::string_view{ error && !std::empty(error.message()) ? error.message() : "unknown error" };
         tr_logAddWarnTor(
             tor,
-            fmt::format(
-                tr_ngettext(
-                    "Couldn't parse magnet metainfo: '{error}'. Redownloading {piece_count} piece",
-                    "Couldn't parse magnet metainfo: '{error}'. Redownloading {piece_count} pieces",
-                    n),
-                fmt::arg("error", msg),
-                fmt::arg("piece_count", n)));
+            fmt::format("Couldn't parse magnet metainfo: '{error}'. Redownloading metadata", fmt::arg("error", msg)));
     }
+
+    m.reset();
 }
 } // namespace set_metadata_piece_helpers
 } // namespace