Squashed 'external/toxcore/c-toxcore/' changes from c9cdae001..9ed2fa80d

9ed2fa80d fix(toxav): remove extra copy of video frame on encode
de30cf3ad docs: Add new file kinds, that should be useful to all clients.
d5b5e879d fix(DHT): Correct node skipping logic timed out nodes.
30e71fe97 refactor: Generate event dispatch functions and add tox_events_dispatch.
8fdbb0b50 style: Format parameter lists in event handlers.
d00dee12b refactor: Add warning logs when losing chat invites.
b144e8db1 feat: Add a way to look up a file number by ID.
849281ea0 feat: Add a way to fetch groups by chat ID.
a2c177396 refactor: Harden event system and improve type safety.
8f5caa656 refactor: Add MessagePack string support to bin_pack.
34e8d5ad5 chore: Add GitHub CodeQL workflow and local Docker runner.
f7b068010 refactor: Add nullability annotations to event headers.
788abe651 refactor(toxav): Use system allocator for mutexes.
2e4b423eb refactor: Use specific typedefs for public API arrays.
2baf34775 docs(toxav): update idle iteration interval see 679444751876fa3882a717772918ebdc8f083354
2f87ac67b feat: Add Event Loop abstraction (Ev).
f8dfc38d8 test: Fix data race in ToxScenario virtual_clock.
38313921e test(TCP): Add regression test for TCP priority queue integrity.
f94a50d9a refactor(toxav): Replace mutable_mutex with dynamically allocated mutex.
ad054511e refactor: Internalize DHT structs and add debug helpers.
8b467cc96 fix: Prevent potential integer overflow in group chat handshake.
4962bdbb8 test: Improve TCP simulation and add tests
5f0227093 refactor: Allow nullable data in group chat handlers.
e97b18ea9 chore: Improve Windows Docker support.
b14943bbd refactor: Move Logger out of Messenger into Tox.
dd3136250 cleanup: Apply nullability qualifiers to C++ codebase.
1849f70fc refactor: Extract low-level networking code to net and os_network.
8fec75421 refactor: Delete tox_random, align on rng and os_random.
a03ae8051 refactor: Delete tox_memory, align on mem and os_memory.
4c88fed2c refactor: Use `std::` prefixes more consistently in C++ code.
72452f2ae test: Add some more tests for onion and shared key cache.
d5a51b09a cleanup: Use tox_attributes.h in tox_private.h and install it.
b6f5b9fc5 test: Add some benchmarks for various high level things.
8a8d02785 test(support): Introduce threaded Tox runner and simulation barrier
d68d1d095 perf(toxav): optimize audio and video intermediate buffers by keeping them around
REVERT: c9cdae001 fix(toxav): remove extra copy of video frame on encode

git-subtree-dir: external/toxcore/c-toxcore
git-subtree-split: 9ed2fa80d582c714d6bdde6a7648220a92cddff8

testing/support/doubles/fake_network_stack_test.cc

@@ -87,5 +87,62 @@ namespace {
         ASSERT_NE(net_socket_to_native(accepted), -1);
     }
 
+    TEST_F(FakeNetworkStackTest, LoopbackRedirection)
+    {
+        // 1. Create a stack with a specific IP (20.0.0.1)
+        FakeNetworkStack my_stack{universe, make_ip(0x14000001)};
+        Socket sock = my_stack.socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
+
+        IP_Port bind_addr;
+        ip_init(&bind_addr.ip, false);
+        bind_addr.ip.ip.v4.uint32 = net_htonl(0x14000001);
+        bind_addr.port = net_htons(12345);
+        ASSERT_EQ(my_stack.bind(sock, &bind_addr), 0);
+        ASSERT_EQ(my_stack.listen(sock, 5), 0);
+
+        // 2. Connect to 127.0.0.1:12345 from the same stack
+        Socket client = my_stack.socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
+
+        IP_Port connect_addr;
+        ip_init(&connect_addr.ip, false);
+        connect_addr.ip.ip.v4.uint32 = net_htonl(0x7F000001);
+        connect_addr.port = net_htons(12345);
+
+        // Should redirect to 20.0.0.1:12345 because 127.0.0.1 is not bound
+        ASSERT_EQ(my_stack.connect(client, &connect_addr), -1);
+        ASSERT_EQ(errno, EINPROGRESS);
+
+        universe.process_events(0);  // SYN
+
+        Socket accepted = my_stack.accept(sock);
+        ASSERT_NE(net_socket_to_native(accepted), -1);
+    }
+
+    TEST_F(FakeNetworkStackTest, ImplicitBindAvoidsCollision)
+    {
+        // Bind server to 33445 (default start of find_free_port)
+        Socket server = stack.socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
+        IP_Port addr;
+        ip_init(&addr.ip, false);
+        addr.ip.ip.v4.uint32 = 0;
+        addr.port = net_htons(33445);
+        ASSERT_EQ(stack.bind(server, &addr), 0);
+
+        // Create client and connect (implicit bind)
+        Socket client = stack.socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
+        IP_Port server_addr;
+        ip_init(&server_addr.ip, false);
+        server_addr.ip.ip.v4.uint32 = net_htonl(0x7F000001);
+        server_addr.port = net_htons(33445);
+
+        // Should find a free port (not 33445)
+        ASSERT_EQ(stack.connect(client, &server_addr), -1);
+        ASSERT_EQ(errno, EINPROGRESS);
+
+        auto *client_obj = stack.get_sock(client);
+        ASSERT_NE(client_obj, nullptr);
+        ASSERT_NE(client_obj->local_port(), 33445);
+    }
+
 }  // namespace
 }  // namespace tox::test