preserve context reference when shadowing Socket classes

tests/test_socket.py

@@ -560,6 +560,7 @@ def test_shadow(self):
         assert s2._shadow_obj is s
         assert s.underlying != p.underlying
         assert s2.underlying == s.underlying
+        assert s2.context is s.context
         s3 = zmq.Socket(s)
         assert s3._shadow_obj is s
         assert s3.underlying == s.underlying

zmq/sugar/socket.py

@@ -133,6 +133,7 @@ def __init__(
         shadow: Socket | int = 0,
         copy_threshold: int | None = None,
     ):
+        shadow_context: zmq.Context | None = None
         if isinstance(ctx_or_socket, zmq.Socket):
             # positional Socket(other_socket)
             shadow = ctx_or_socket
@@ -145,6 +146,8 @@ def __init__(
             # hold a reference to the shadow object
             self._shadow_obj = shadow
             if not isinstance(shadow, int):
+                if isinstance(shadow, zmq.Socket):
+                    shadow_context = shadow.context
                 try:
                     shadow = cast(int, shadow.underlying)
                 except AttributeError:
@@ -159,6 +162,9 @@ def __init__(
             shadow=shadow_address,
             copy_threshold=copy_threshold,
         )
+        if self._shadow_obj and shadow_context:
+            # keep self.context reference if shadowing a Socket object
+            self.context = shadow_context
 
         try:
             socket_type = cast(int, self.get(zmq.TYPE))