From 527a0b650cc9ea93b266177422ca3f58bd8c4745 Mon Sep 17 00:00:00 2001
From: Thomas Farstrike <111072251+ThomasFarstrike@users.noreply.github.com>
Date: Tue, 11 Nov 2025 23:14:52 +0100
Subject: [PATCH] fix: correctly handle WebSocket message fragmentation

Handle WebSocket fragmentation was properly by taking into account the "fin" flag to know if a frame is "final" or whether there will be continuations before it's final.

Signed-off-by: Thomas Farstrike <111072251+ThomasFarstrike@users.noreply.github.com>
---
 python-ecosys/aiohttp/aiohttp/aiohttp_ws.py | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/python-ecosys/aiohttp/aiohttp/aiohttp_ws.py b/python-ecosys/aiohttp/aiohttp/aiohttp_ws.py
index 53a640fe5..0510f494b 100644
--- a/python-ecosys/aiohttp/aiohttp/aiohttp_ws.py
+++ b/python-ecosys/aiohttp/aiohttp/aiohttp_ws.py
@@ -166,7 +166,10 @@ async def handshake(self, uri, ssl, req):
 
     async def receive(self):
         while True:
-            opcode, payload = await self._read_frame()
+            opcode, payload, final = await self._read_frame()
+            while not final:
+                _, morepayload, final = await self._read_frame() # original opcode must be preserved
+                payload += morepayload
             send_opcode, data = self._process_websocket_frame(opcode, payload)
             if send_opcode:  # pragma: no cover
                 await self.send(data, send_opcode)
@@ -206,7 +209,7 @@ async def _read_frame(self):
         payload = await self.reader.readexactly(length)
         if has_mask:  # pragma: no cover
             payload = bytes(x ^ mask[i % 4] for i, x in enumerate(payload))
-        return opcode, payload
+        return opcode, payload, fin
 
 
 class ClientWebSocketResponse: