fix issue where trackers from magnet links were not included in create_torrent()

ChangeLog

@@ -1,3 +1,4 @@
+	* fix issue where trackers from magnet links were not included in create_torrent()
 	* make peer_info::client a byte array in python binding
 	* pick contiguous pieces from peers with high download rate
 	* fix error handling of moving storage to a drive letter that isn't mounted

bindings/python/src/torrent_info.cpp

@@ -234,6 +234,15 @@ void bind_torrent_info()
         .def_readwrite("size", &file_slice::size)
         ;
 
+    enum_<announce_entry::tracker_source>("tracker_source")
+        .value("source_torrent", announce_entry::source_torrent)
+        .value("source_client", announce_entry::source_client)
+        .value("source_magnet_link", announce_entry::source_magnet_link)
+        .value("source_tex", announce_entry::source_tex)
+    ;
+
+    using add_tracker1 = void (torrent_info::*)(std::string const&, int, announce_entry::tracker_source);
+
     class_<torrent_info, std::shared_ptr<torrent_info>>("torrent_info", no_init)
         .def(init<sha1_hash const&>(arg("info_hash")))
         .def("__init__", make_constructor(&bencoded_constructor0))
@@ -245,7 +254,7 @@ void bind_torrent_info()
         .def(init<std::wstring>((arg("file"))))
 #endif
 
-        .def("add_tracker", &torrent_info::add_tracker, arg("url"))
+        .def("add_tracker", (add_tracker1)&torrent_info::add_tracker, arg("url"), arg("tier") = 0, arg("source") = announce_entry::source_client)
         .def("add_url_seed", &torrent_info::add_url_seed)
         .def("add_http_seed", &torrent_info::add_http_seed)
         .def("web_seeds", get_web_seeds)
@@ -339,13 +348,6 @@ void bind_torrent_info()
         .def("trim", &announce_entry::trim)
         ;
 
-    enum_<announce_entry::tracker_source>("tracker_source")
-        .value("source_torrent", announce_entry::source_torrent)
-        .value("source_client", announce_entry::source_client)
-        .value("source_magnet_link", announce_entry::source_magnet_link)
-        .value("source_tex", announce_entry::source_tex)
-    ;
-
     implicitly_convertible<std::shared_ptr<torrent_info>, std::shared_ptr<const torrent_info>>();
     boost::python::register_ptr_to_python<std::shared_ptr<const torrent_info>>();
 }

include/libtorrent/torrent_handle.hpp

@@ -831,8 +831,7 @@ namespace aux {
 		// If the torrent doesn't have metadata, the pointer will not be
 		// initialized (i.e. a nullptr). The torrent may be in a state
 		// without metadata only if it was started without a .torrent file, e.g.
-		// by using the libtorrent extension of just supplying a tracker and
-		// info-hash.
+		// by being added by magnet link
 		std::shared_ptr<const torrent_info> torrent_file() const;
 
 #if TORRENT_ABI_VERSION == 1

include/libtorrent/torrent_info.hpp

@@ -51,10 +51,7 @@ POSSIBILITY OF SUCH DAMAGE.
 #include "libtorrent/sha1_hash.hpp"
 #include "libtorrent/file_storage.hpp"
 #include "libtorrent/aux_/vector.hpp"
-
-#if TORRENT_COMPLETE_TYPES_REQUIRED
 #include "libtorrent/announce_entry.hpp"
-#endif
 
 namespace libtorrent {
 
@@ -267,6 +264,8 @@ namespace libtorrent {
 		// lower tier will always be tried before the one with higher tier
 		// number. For more information, see announce_entry_.
 		void add_tracker(std::string const& url, int tier = 0);
+		void add_tracker(std::string const& url, int tier
+			, announce_entry::tracker_source source);
 		std::vector<announce_entry> const& trackers() const { return m_urls; }
 
 		// These two functions are related to `BEP 38`_ (mutable torrents). The

src/torrent.cpp

@@ -252,6 +252,14 @@ bool is_downloading_state(int const st)
 		if (!m_torrent_file)
 			m_torrent_file = (p.ti ? p.ti : std::make_shared<torrent_info>(m_info_hash));
 
+		// in case we added the torrent via magnet link, make sure to preserve any
+		// DHT nodes passed in on the URI in the torrent file itself
+		if (!m_torrent_file->is_valid())
+		{
+			for (auto const& n : p.dht_nodes)
+				m_torrent_file->add_node(n);
+		}
+
 		// --- WEB SEEDS ---
 
 		// if override web seed flag is set, don't load any web seeds from the
@@ -274,10 +282,16 @@ bool is_downloading_state(int const st)
 			// correct URLs to end with a "/" for multi-file torrents
 			if (multi_file)
 				ensure_trailing_slash(ws.back().url);
+			if (!m_torrent_file->is_valid())
+				m_torrent_file->add_url_seed(ws.back().url);
 		}
 
 		for (auto const& e : p.http_seeds)
+		{
 			ws.emplace_back(e, web_seed_entry::http_seed);
+			if (!m_torrent_file->is_valid())
+				m_torrent_file->add_http_seed(e);
+		}
 
 		aux::random_shuffle(ws);
 		for (auto& w : ws) m_web_seeds.emplace_back(std::move(w));
@@ -305,6 +319,11 @@ bool is_downloading_state(int const st)
 			if (!find_tracker(e.url))
 			{
 				m_trackers.push_back(e);
+				// add the tracker to the m_torrent_file here so that the trackers
+				// will be preserved via create_torrent() when passing in just the
+				// torrent_info object.
+				if (!m_torrent_file->is_valid())
+					m_torrent_file->add_tracker(e.url, e.tier, announce_entry::tracker_source(e.source));
 			}
 		}
 
@@ -6067,7 +6086,7 @@ bool is_downloading_state(int const st)
 
 	std::shared_ptr<const torrent_info> torrent::get_torrent_copy()
 	{
-		if (!m_torrent_file->is_valid()) return std::shared_ptr<const torrent_info>();
+		if (!m_torrent_file->is_valid()) return {};
 		return m_torrent_file;
 	}
 

src/torrent_info.cpp

@@ -1510,6 +1510,12 @@ namespace {
 	}
 
 	void torrent_info::add_tracker(std::string const& url, int const tier)
+	{
+		add_tracker(url, tier, announce_entry::source_client);
+	}
+
+	void torrent_info::add_tracker(std::string const& url, int const tier
+		, announce_entry::tracker_source const source)
 	{
 		auto const i = std::find_if(m_urls.begin(), m_urls.end()
 			, [&url](announce_entry const& ae) { return ae.url == url; });
@@ -1517,7 +1523,7 @@ namespace {
 
 		announce_entry e(url);
 		e.tier = std::uint8_t(tier);
-		e.source = announce_entry::source_client;
+		e.source = source;
 		m_urls.push_back(e);
 
 		std::sort(m_urls.begin(), m_urls.end()

test/test_magnet.cpp

@@ -432,6 +432,48 @@ TORRENT_TEST(trailing_whitespace)
 	TEST_CHECK(h.is_valid());
 }
 
+// These tests don't work because we don't hand out an incomplete torrent_info
+// object. To make them work we would either have to set the correct metadata in
+// the test, or change the behavior to make `h.torrent_file()` return the
+// internal torrent_info object unconditionally
+/*
+TORRENT_TEST(preserve_trackers)
+{
+	session ses(settings());
+	error_code ec;
+	add_torrent_params p = parse_magnet_uri("magnet:?xt=urn:btih:abaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa&tr=https://test.com/announce", ec);
+	p.save_path = ".";
+	torrent_handle h = ses.add_torrent(p);
+	TEST_CHECK(h.is_valid());
+	TEST_CHECK(h.torrent_file()->trackers().size() == 1);
+	TEST_CHECK(h.torrent_file()->trackers().at(0).url == "https://test.com/announce");
+}
+
+TORRENT_TEST(preserve_web_seeds)
+{
+	session ses(settings());
+	error_code ec;
+	add_torrent_params p = parse_magnet_uri("magnet:?xt=urn:btih:abaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa&ws=https://test.com/test", ec);
+	p.save_path = ".";
+	torrent_handle h = ses.add_torrent(p);
+	TEST_CHECK(h.is_valid());
+	TEST_CHECK(h.torrent_file()->web_seeds().size() == 1);
+	TEST_CHECK(h.torrent_file()->web_seeds().at(0).url == "https://test.com/test");
+}
+
+TORRENT_TEST(preserve_dht_nodes)
+{
+	session ses(settings());
+	error_code ec;
+	add_torrent_params p = parse_magnet_uri("magnet:?xt=urn:btih:abaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa&dht=test:1234", ec);
+	p.save_path = ".";
+	torrent_handle h = ses.add_torrent(p);
+	TEST_CHECK(h.is_valid());
+	TEST_CHECK(h.torrent_file()->nodes().size() == 1);
+	TEST_CHECK(h.torrent_file()->nodes().at(0).first == "test");
+	TEST_CHECK(h.torrent_file()->nodes().at(0).second == 1234);
+}
+*/
 TORRENT_TEST(invalid_tracker_escaping)
 {
 	error_code ec;