Review fixes

aio_pika/channel.py

@@ -101,7 +101,10 @@ def is_closed(self) -> bool:
         side or after the close() method has been called."""
         if not self.is_initialized or self._closed:
             return True
-        return self.channel.is_closed
+        channel = self._channel
+        if channel is None:
+            return True
+        return channel.channel.is_closed
 
     async def close(
         self,
@@ -161,13 +164,14 @@ async def _open(self) -> None:
             channel_number=self._channel_number,
         )
 
+        self._channel = channel
         try:
-            self._channel = channel
             await self._on_open()
-            self._closed = False
-        except Exception as e:
+        except BaseException as e:
             await channel.close(e)
+            self._channel = None
             raise
+        self._closed = False
 
     async def initialize(self, timeout: TimeoutType = None) -> None:
         if self.is_initialized:

aio_pika/robust_channel.py

@@ -89,6 +89,10 @@ async def restore(self) -> None:
 
     async def __close_callback(self, _: Any, exc: BaseException) -> None:
         if isinstance(exc, asyncio.CancelledError):
+            # This happens only if the channel is forced to close from the
+            # outside, for example, if the connection is closed.
+            # Of course, here you need to exit fron this function
+            # as soon as possible and to avoid a recovery attempt.
             return
 
         in_restore_state = not self.__restored

tests/test_amqp.py

@@ -877,6 +877,11 @@ async def test_wrong_credentials(
     async def test_set_qos(self, channel: aio_pika.Channel):
         await channel.set_qos(prefetch_count=1, global_=True)
 
+    async def test_set_qos_deprecated_all_channels(
+        self, channel: aio_pika.Channel
+    ):
+        await channel.set_qos(prefetch_count=1, all_channels=True)
+
     async def test_exchange_delete(
         self, channel: aio_pika.Channel, declare_exchange,
     ):