gh-157418: Correct the IocpProactor.recvfrom_into() parameter name (#157422)

Author: lpyu001

Lib/asyncio/windows_events.py

@@ -515,11 +515,11 @@ def recvfrom(self, conn, nbytes, flags=0):
         return self._register(ov, conn, partial(self._finish_recvfrom,
                                                 empty_result=b''))
 
-    def recvfrom_into(self, conn, buf, flags=0):
+    def recvfrom_into(self, conn, buf, nbytes=0):
         self._register_with_iocp(conn)
         ov = _overlapped.Overlapped(NULL)
         try:
-            ov.WSARecvFromInto(conn.fileno(), buf, flags)
+            ov.WSARecvFromInto(conn.fileno(), buf, nbytes)
         except BrokenPipeError:
             return self._result((0, None))
 

Misc/NEWS.d/next/Windows/2026-09-14-16-49-44.gh-issue-157418.r2IggA.rst

@@ -0,0 +1,3 @@
+Correct the third parameter name of ``IocpProactor.recvfrom_into()`` from
+*flags* to *nbytes* to reflect that it specifies the number of bytes to
+receive.