gh-127529: Correct asyncio's `accept_connection` behaviour for handling `ConnectionAbortedError` (#127532)

Co-authored-by: Kumar Aditya <kumaraditya@python.org>

1 files changed, 7 insertions, 3 deletions

diff --git a/Lib/asyncio/selector_events.py b/Lib/asyncio/selector_events.py
index f1ab9b1..50992a6 100644
--- a/Lib/asyncio/selector_events.py
+++ b/Lib/asyncio/selector_events.py
@@ -180,9 +180,13 @@ class BaseSelectorEventLoop(base_events.BaseEventLoop):
                     logger.debug("%r got a new connection from %r: %r",
                                  server, addr, conn)
                 conn.setblocking(False)
-            except (BlockingIOError, InterruptedError, ConnectionAbortedError):
-                # Early exit because the socket accept buffer is empty.
-                return None
+            except ConnectionAbortedError:
+                # Discard connections that were aborted before accept().
+                continue
+            except (BlockingIOError, InterruptedError):
+                # Early exit because of a signal or
+                # the socket accept buffer is empty.
+                return
             except OSError as exc:
                 # There's nowhere to send the error, so just log it.
                 if exc.errno in (errno.EMFILE, errno.ENFILE,