From 211e3fc98571f3b55d17b1ff38facdc02762e3ad Mon Sep 17 00:00:00 2001
From: Charles Kerr <charles@charleskerr.com>
Date: Wed, 1 Mar 2023 13:10:20 -0600
Subject: [PATCH] fix: always add `announce` key even when including
 announce-list (#5106)

---
 libtransmission/makemeta.cc            |  6 ++-
 tests/libtransmission/makemeta-test.cc | 75 +++++++++++++++++++++++---
 2 files changed, 74 insertions(+), 7 deletions(-)

diff --git a/libtransmission/makemeta.cc b/libtransmission/makemeta.cc
index 4c6c029f6..108b78f1a 100644
--- a/libtransmission/makemeta.cc
+++ b/libtransmission/makemeta.cc
@@ -291,8 +291,12 @@ std::string tr_metainfo_builder::benc(tr_error** error) const
     auto top = tr_variant{};
     tr_variantInitDict(&top, 8);
 
-    // add the announce-list trackers
+    // add the announce URLs
     if (!std::empty(announceList()))
+    {
+        tr_variantDictAddStrView(&top, TR_KEY_announce, announceList().at(0).announce.sv());
+    }
+    if (std::size(announceList()) > 1U)
     {
         auto* const announce_list = tr_variantDictAddList(&top, TR_KEY_announce_list, 0);
         tr_variant* tier_list = nullptr;
diff --git a/tests/libtransmission/makemeta-test.cc b/tests/libtransmission/makemeta-test.cc
index 96c50112b..af4c95768 100644
--- a/tests/libtransmission/makemeta-test.cc
+++ b/tests/libtransmission/makemeta-test.cc
@@ -216,6 +216,69 @@ TEST_F(MakemetaTest, singleFile)
     testBuilder(builder);
 }
 
+TEST_F(MakemetaTest, announceSingleTracker)
+{
+    auto const files = makeRandomFiles(sandboxDir(), 1);
+    auto const [filename, payload] = files.front();
+    auto builder = tr_metainfo_builder{ filename };
+
+    // add a tracker
+    static auto constexpr SingleAnnounce = "udp://tracker.openbittorrent.com:80"sv;
+    auto trackers = tr_announce_list{};
+    trackers.add(SingleAnnounce, trackers.nextTier());
+    builder.setAnnounceList(std::move(trackers));
+
+    // generate the torrent and parse it as a variant
+    EXPECT_EQ(nullptr, builder.makeChecksums().get());
+    auto top = tr_variant{};
+    auto const benc = builder.benc();
+    EXPECT_TRUE(tr_variantFromBuf(&top, TR_VARIANT_PARSE_BENC | TR_VARIANT_PARSE_INPLACE, benc));
+
+    // confirm there's an "announce" entry
+    auto single_announce = std::string_view{};
+    EXPECT_TRUE(tr_variantDictFindStrView(&top, TR_KEY_announce, &single_announce));
+    EXPECT_EQ(SingleAnnounce, single_announce);
+
+    // confirm there's not an "announce-list" entry
+    EXPECT_EQ(nullptr, tr_variantDictFind(&top, TR_KEY_announce_list));
+
+    tr_variantClear(&top);
+}
+
+TEST_F(MakemetaTest, announceMultiTracker)
+{
+    auto const files = makeRandomFiles(sandboxDir(), 1);
+    auto const [filename, payload] = files.front();
+    auto builder = tr_metainfo_builder{ filename };
+
+    // add the trackers
+    auto trackers = tr_announce_list{};
+    for (auto const& url : { "udp://tracker.openbittorrent.com:80"sv, "udp://tracker.publicbt.com:80"sv })
+    {
+        trackers.add(url, trackers.nextTier());
+    }
+    builder.setAnnounceList(std::move(trackers));
+
+    // generate the torrent and parse it as a variant
+    EXPECT_EQ(nullptr, builder.makeChecksums().get());
+    auto top = tr_variant{};
+    auto const benc = builder.benc();
+    EXPECT_TRUE(tr_variantFromBuf(&top, TR_VARIANT_PARSE_BENC | TR_VARIANT_PARSE_INPLACE, benc));
+
+    // confirm there's an "announce" entry
+    auto single_announce = std::string_view{};
+    EXPECT_TRUE(tr_variantDictFindStrView(&top, TR_KEY_announce, &single_announce));
+    EXPECT_EQ(builder.announceList().at(0).announce.sv(), single_announce);
+
+    // confirm there's an "announce-list" entry
+    tr_variant* announce_list_variant = nullptr;
+    EXPECT_TRUE(tr_variantDictFindList(&top, TR_KEY_announce_list, &announce_list_variant));
+    EXPECT_NE(nullptr, announce_list_variant);
+    EXPECT_EQ(std::size(builder.announceList()), tr_variantListSize(announce_list_variant));
+
+    tr_variantClear(&top);
+}
+
 TEST_F(MakemetaTest, privateAndSourceHasDifferentInfoHash)
 {
     auto const files = makeRandomFiles(sandboxDir(), 1);
@@ -224,16 +287,16 @@ TEST_F(MakemetaTest, privateAndSourceHasDifferentInfoHash)
     auto trackers = tr_announce_list{};
     trackers.add("udp://tracker.openbittorrent.com:80"sv, trackers.nextTier());
     builder.setAnnounceList(std::move(trackers));
-    auto baseMetainfo = testBuilder(builder);
+    auto base_metainfo = testBuilder(builder);
 
     builder.setPrivate(true);
-    auto privateMetainfo = testBuilder(builder);
-    EXPECT_NE(baseMetainfo.infoHash(), privateMetainfo.infoHash());
+    auto private_metainfo = testBuilder(builder);
+    EXPECT_NE(base_metainfo.infoHash(), private_metainfo.infoHash());
 
     builder.setSource("FOO");
-    auto privateSourceMetainfo = testBuilder(builder);
-    EXPECT_NE(baseMetainfo.infoHash(), privateSourceMetainfo.infoHash());
-    EXPECT_NE(privateMetainfo.infoHash(), privateSourceMetainfo.infoHash());
+    auto private_source_metainfo = testBuilder(builder);
+    EXPECT_NE(base_metainfo.infoHash(), private_source_metainfo.infoHash());
+    EXPECT_NE(private_metainfo.infoHash(), private_source_metainfo.infoHash());
 }
 
 } // namespace libtransmission::test