Fix missing 26.50 blocks and connected shapes on older servers

CHANGELOG.md

@@ -6,6 +6,9 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/).
 
 ## [Unreleased]
 
+### Fixed
+- Stairs, fences, panes, bars, and tripwire could disappear for 26.50 clients on 26.40-26.45 servers. Existing blocks now load with the correct states, stair corners and connections follow neighboring blocks, and placing or removing blocks refreshes nearby shapes.
+
 ## [0.5.1] - 2026-09-15
 
 ### Fixed

pyproject.toml

@@ -57,7 +57,7 @@ minimum-version = "build-system.requires"
 build-dir = "build/{wheel_tag}"
 wheel.packages = ["src/endweave"]
 wheel.py-api = "cp312"
-wheel.exclude = ["**/*.cpp", "**/*.h", "**/*.pat", "**/CMakeLists.txt"]
+wheel.exclude = ["**/*.cpp", "**/*.h", "**/*.inc", "**/*.pat", "**/CMakeLists.txt"]
 install.components = ["python"]
 sdist.exclude = [".github", "build", "tests"]
 
@@ -80,4 +80,4 @@ provider = "scikit_build_core.metadata.setuptools_scm"
 
 [tool.setuptools_scm]
 version_file = "src/endweave/_version.py"
-local_scheme = "no-local-version"
+local_scheme = "no-local-version"

src/endweave/_pipeline.cpp

@@ -5,7 +5,9 @@
 
 #include <bedrock/protocol/network.h>
 #include <nanobind/nanobind.h>
+#include <nanobind/stl/function.h>
 #include <nanobind/stl/optional.h>
+#include <nanobind/stl/pair.h>
 #include <nanobind/stl/string.h>
 #include <nanobind/stl/vector.h>
 #include <optional>
@@ -69,7 +71,8 @@ struct Translator {
     int to_version = 0;
 };
 
-std::optional<nb::bytes> translate(const Translator &translator, int packet_id, nb::bytes payload)
+std::optional<nb::bytes> translateImpl(const Translator &translator, int packet_id, nb::bytes payload,
+                                       endweave::blocks::WorldContext *world)
 {
     const endweave::PacketHandler handler = translator.engine.get(packet_id);
     if (handler == nullptr) {
@@ -81,7 +84,7 @@ std::optional<nb::bytes> translate(const Translator &translator, int packet_id,
     bp::BinaryWriter out{translated};
     bp::BinaryReader in{std::string_view{payload.c_str(), payload.size()}};
     bool cancelled = false;
-    const auto result = handler(cancelled, in, out);
+    const auto result = handler(cancelled, in, out, world);
     if (!result) {
         raiseTranslationError(packet_id, "translate", result.error());
     }
@@ -91,6 +94,27 @@ std::optional<nb::bytes> translate(const Translator &translator, int packet_id,
     return nb::bytes(translated.data(), translated.size());
 }
 
+std::optional<nb::bytes> translate(const Translator &translator, int packet_id, nb::bytes payload)
+{
+    return translateImpl(translator, packet_id, payload, nullptr);
+}
+
+std::pair<std::optional<nb::bytes>, std::vector<nb::bytes>> translateWorld(const Translator &translator, int packet_id,
+                                                                           nb::bytes payload,
+                                                                           endweave::blocks::Lookup lookup,
+                                                                           int dimension)
+{
+    endweave::blocks::WorldContext world{std::move(lookup), dimension, {}, {}};
+    auto result = translateImpl(translator, packet_id, payload, &world);
+    std::vector<nb::bytes> updates;
+    if (result) {
+        for (const auto &update : endweave::blocks::neighborUpdates(world)) {
+            updates.emplace_back(update.data(), update.size());
+        }
+    }
+    return {std::move(result), std::move(updates)};
+}
+
 } // namespace
 
 NB_MODULE(_pipeline, m)
@@ -141,6 +165,8 @@ NB_MODULE(_pipeline, m)
                 return self.actions;
             },
             "The action for each packet id that needs one. Other ids pass through untouched.")
+        .def("translate_world", &translateWorld, "packet_id"_a, "payload"_a, "lookup"_a, "dimension"_a,
+             "Translate blocks using a dimension/x/y/z lookup; return payload and neighbor UpdateBlock payloads.")
         .def("translate", &translate, "packet_id"_a, "payload"_a,
              "The translated payload, or None if the packet was cancelled.");
 }

src/endweave/_pipeline.pyi

@@ -1,6 +1,6 @@
 """Compile-time protocol translation between Bedrock versions."""
 
-from collections.abc import Mapping
+from collections.abc import Callable, Mapping
 import enum
 
 
@@ -36,6 +36,11 @@ class Translator:
         The action for each packet id that needs one. Other ids pass through untouched.
         """
 
+    def translate_world(self, packet_id: int, payload: bytes, lookup: Callable[[int, int, int, int], int], dimension: int) -> tuple[bytes | None, list[bytes]]:
+        """
+        Translate blocks using a dimension/x/y/z lookup; return payload and neighbor UpdateBlock payloads.
+        """
+
     def translate(self, packet_id: int, payload: bytes) -> bytes | None:
         """The translated payload, or None if the packet was cancelled."""
 

src/endweave/connection.py

@@ -72,6 +72,7 @@ def __init__(self, address: str, server_protocol_version: ProtocolVersion) -> No
         self.player: Player | None = None
         self.active = True
         self.pending_disconnect = False
+        self.sending_block_updates = False
 
     @property
     def id(self) -> int:

src/endweave/plugin.py

@@ -157,6 +157,8 @@ def on_packet_receive(self, event: PacketReceiveEvent) -> None:
     def on_packet_send(self, event: PacketSendEvent) -> None:
         connection = self._connection_manager.get_connection(str(event.address))
         if connection is not None:
+            if connection.sending_block_updates and event.packet_id == 21:
+                return
             self._translate(connection, event, Direction.CLIENTBOUND)
 
     def _translate(
@@ -200,8 +202,25 @@ def _translate(
         if logged and debug.log_pre_packet_transform:
             self.logger.info(f"[{direction.value}] {label} in: {event.payload.hex()}")
 
+        neighbor_updates: list[bytes] = []
         try:
-            payload = translator.translate(packet_id, event.payload)
+            if (
+                direction is Direction.CLIENTBOUND
+                and translator.from_version < 2193 <= translator.to_version
+                and packet_id in (21, 58, 110, 172, 174)
+                and connection.player is not None
+            ):
+                player_dimension = connection.player.dimension
+                dimensions = {dimension.type.value: dimension for dimension in player_dimension.level.dimensions}
+
+                def lookup_block(dimension_id: int, x: int, y: int, z: int) -> int:
+                    return dimensions[dimension_id].get_block_at(x, y, z).data.runtime_id
+
+                payload, neighbor_updates = translator.translate_world(
+                    packet_id, event.payload, lookup_block, player_dimension.type.value
+                )
+            else:
+                payload = translator.translate(packet_id, event.payload)
         except TranslationError as error:
             debug.log_translation_failure(
                 f"Failed to translate {direction.value} packet {_packet_label(packet_id)} "
@@ -230,6 +249,13 @@ def _translate(
             self.logger.info(f"[{direction.value}] {label} out: {payload.hex()}")
 
         event.payload = payload
+        if neighbor_updates and connection.player is not None:
+            connection.sending_block_updates = True
+            try:
+                for update in neighbor_updates:
+                    connection.player.send_packet(21, update)
+            finally:
+                connection.sending_block_updates = False
 
     @event_handler
     def on_player_login(self, event: PlayerLoginEvent) -> None:

src/endweave/protocol/handler.h

@@ -3,6 +3,7 @@
 #include "endweave/protocol/rewrite.h"
 #include "endweave/protocol/transform.h"
 #include "endweave/protocol/version.h"
+#include "endweave/protocols/blocks.h"
 #include "endweave/protocols/rewriters.h"
 #include "endweave/protocols/v2168_to_v2193/transform.h"
 #include "endweave/protocols/v2193_to_v2168/transform.h"
@@ -45,7 +46,8 @@ inline constexpr bool should_cancel_v =
 template <int From, int To, int Id>
 inline constexpr bool should_translate_v =
     From != To && !(Id >= kSkipBegin && Id <= kSkipEnd) && path_has_packet_v<From, To, Id> &&
-    (Rewritable<From, To, Id> || !std::is_same_v<bp::packet_of_t<From, Id>, bp::packet_of_t<To, Id>>);
+    (Rewritable<From, To, Id> || blocks::needs_rewrite<From, To, Id> ||
+     !std::is_same_v<bp::packet_of_t<From, Id>, bp::packet_of_t<To, Id>>);
 
 template <int Cur, int To, int Id>
 void chain(const Context<bp::packet_of_t<To, Id>> &ctx, bp::packet_of_t<Cur, Id> &&from)
@@ -68,7 +70,8 @@ void chain(const Context<bp::packet_of_t<To, Id>> &ctx, bp::packet_of_t<Cur, Id>
 }
 
 template <int From, int To, int Id>
-std::expected<void, std::error_code> handle(bool &cancelled, bp::BinaryReader &in, bp::BinaryWriter &out)
+std::expected<void, std::error_code> handle(bool &cancelled, bp::BinaryReader &in, bp::BinaryWriter &out,
+                                            blocks::WorldContext *world)
 {
     auto result = bp::deserialize<bp::packet_of_t<From, Id>>(in);
     if (!result) {
@@ -82,6 +85,12 @@ std::expected<void, std::error_code> handle(bool &cancelled, bp::BinaryReader &i
     std::string translated;
     bp::BinaryWriter writer{translated};
     auto &&packet = std::move(result).value();
+    if constexpr (blocks::needs_rewrite<From, To, Id>) {
+        auto rewritten = blocks::rewrite<From, To, Id>(packet, world);
+        if (!rewritten) {
+            return std::unexpected(rewritten.error());
+        }
+    }
     if constexpr (Rewritable<From, To, Id>) {
         Rewriter<From, To, Id>::rewrite(packet);
     }
@@ -114,7 +123,8 @@ std::expected<void, std::error_code> handle(bool &cancelled, bp::BinaryReader &i
 }
 
 /** @see ViaVersion PacketWrapper#cancel. */
-inline std::expected<void, std::error_code> cancel(bool &cancelled, bp::BinaryReader &, bp::BinaryWriter &)
+inline std::expected<void, std::error_code> cancel(bool &cancelled, bp::BinaryReader &, bp::BinaryWriter &,
+                                                   blocks::WorldContext *)
 {
     cancelled = true;
     return {};
@@ -130,7 +140,8 @@ enum class Action : char {
 };
 
 /** @see ViaVersion PacketHandler. */
-using PacketHandler = std::expected<void, std::error_code> (*)(bool &, bp::BinaryReader &, bp::BinaryWriter &);
+using PacketHandler = std::expected<void, std::error_code> (*)(bool &, bp::BinaryReader &, bp::BinaryWriter &,
+                                                               blocks::WorldContext *);
 
 namespace detail {
 

src/endweave/protocols/CMakeLists.txt

@@ -1,2 +1,3 @@
+target_sources(_pipeline PRIVATE blocks.cpp)
 add_subdirectory(v2168_to_v2193)
 add_subdirectory(v2193_to_v2168)