Clear stale sign data when signs break

mosfet/protocol/managers.py

@@ -283,11 +283,21 @@ class WorldState:
         return chunk.get_block_at(floor(x), floor(y), floor(z))
 
     def set_block_entity(self, position, entity_type, data):
-        self.block_entities[tuple(position)] = {
+        position = tuple(position)
+        if data is None:
+            self.block_entities.pop(position, None)
+            return
+        self.block_entities[position] = {
             'type': entity_type,
             'data': nbt_plain(data),
         }
 
+    @staticmethod
+    def _is_sign_state(block_state_id):
+        from mosfet.info import blocks
+        name = blocks.BLOCKS.get(block_state_id)
+        return name is not None and name.endswith('_sign')
+
     def set_block_at(self, x, y, z, block_state_id):
         x, y, z = floor(x), floor(y), floor(z)
         chunk = self.get_chunk(floor(x / 16), floor(z / 16))
@@ -297,6 +307,9 @@ class WorldState:
         pos = (x, y, z)
         if previous in self.indexed_ids:
             self.index.get(previous, set()).discard(pos)
+        if (self._is_sign_state(previous) and
+                not self._is_sign_state(block_state_id)):
+            self.block_entities.pop(pos, None)
         if block_state_id in self.indexed_ids:
             self.index.setdefault(block_state_id, set()).add(pos)
         return True