Fix unrecoverable connection state (#3905)

* Fix unrecoverable connection state

* Raise OSError instead

* Also raise OSError in can_read_destructive() in _AsyncHiredisParser

* Raise ConnectionError in on_connect()

---------

Co-authored-by: petyaslavova <petya.slavova@redis.com>

Author: itssimon

redis/_parsers/base.py

@@ -35,7 +35,6 @@
     NoScriptError,
     OutOfMemoryError,
     ReadOnlyError,
-    RedisError,
     ResponseError,
     TryAgainError,
 )
@@ -415,7 +414,7 @@ def on_connect(self, connection):
         """Called when the stream connects"""
         self._stream = connection._reader
         if self._stream is None:
-            raise RedisError("Buffer is closed.")
+            raise ConnectionError(SERVER_CLOSED_CONNECTION_ERROR)
         self.encoder = connection.encoder
         self._clear()
         self._connected = True
@@ -426,7 +425,7 @@ def on_disconnect(self):
 
     async def can_read_destructive(self) -> bool:
         if not self._connected:
-            raise RedisError("Buffer is closed.")
+            raise OSError("Buffer is closed.")
         if self._buffer:
             return True
         try:

redis/_parsers/hiredis.py

@@ -238,7 +238,7 @@ def on_disconnect(self):
 
     async def can_read_destructive(self):
         if not self._connected:
-            raise ConnectionError(SERVER_CLOSED_CONNECTION_ERROR)
+            raise OSError("Buffer is closed.")
         if self._reader.gets() is not NOT_ENOUGH_DATA:
             return True
         try: