From f7e4246114ce48335f224f36c2d4b058b02bea7b Mon Sep 17 00:00:00 2001
From: "patchback[bot]" <45432694+patchback[bot]@users.noreply.github.com>
Date: Mon, 28 Nov 2022 20:29:16 +0000
Subject: [PATCH] [PR #6916/abafcdac backport][3.9] Add missing __repr__ to
 streams.EmptyStreamReader (#7106)

**This is a backport of PR #6916 as merged into master
(abafcdac6cbef06bc555cb77b1ebe724d2a098ec).**

**EmptyStreamReader** currently inherits `__repr__` from
**StreamReader** , which then tries to access non-existing fields,
causing AttributeErrors. The bug causes issues like this in upstream
code: https://github.com/miguelgrinberg/python-socketio/issues/1032

This PR adds a custom `__repr__` to EmptyStreamReader to fix the
problem.

Co-authored-by: elonen <elonen@iki.fi>
---
 CHANGES/6916.bugfix   | 1 +
 CONTRIBUTORS.txt      | 1 +
 aiohttp/streams.py    | 3 +++
 tests/test_streams.py | 1 +
 4 files changed, 6 insertions(+)
 create mode 100644 CHANGES/6916.bugfix

diff --git a/CHANGES/6916.bugfix b/CHANGES/6916.bugfix
new file mode 100644
index 00000000000..4c4329c1abe
--- /dev/null
+++ b/CHANGES/6916.bugfix
@@ -0,0 +1 @@
+Add __repr__ to EmptyStreamReader to avoid AttributeErrors.
diff --git a/CONTRIBUTORS.txt b/CONTRIBUTORS.txt
index 23ea188a074..7c633b30169 100644
--- a/CONTRIBUTORS.txt
+++ b/CONTRIBUTORS.txt
@@ -155,6 +155,7 @@ Jake Davis
 Jakob Ackermann
 Jakub Wilk
 Jan Buchar
+Jarno Elonen
 Jashandeep Sohi
 Jean-Baptiste Estival
 Jens Steinhauser
diff --git a/aiohttp/streams.py b/aiohttp/streams.py
index d5f4c2baaf8..32ec7f148f6 100644
--- a/aiohttp/streams.py
+++ b/aiohttp/streams.py
@@ -502,6 +502,9 @@ class EmptyStreamReader(StreamReader):  # lgtm [py/missing-call-to-init]
     def __init__(self) -> None:
         pass
 
+    def __repr__(self) -> str:
+        return "<%s>" % self.__class__.__name__
+
     def exception(self) -> Optional[BaseException]:
         return None
 
diff --git a/tests/test_streams.py b/tests/test_streams.py
index a16f7ebf4ad..29eab256578 100644
--- a/tests/test_streams.py
+++ b/tests/test_streams.py
@@ -1132,6 +1132,7 @@ async def test_unread_empty(self) -> None:
 
 async def test_empty_stream_reader() -> None:
     s = streams.EmptyStreamReader()
+    assert str(s) is not None
     assert s.set_exception(ValueError()) is None
     assert s.exception() is None
     assert s.feed_eof() is None