Add manual tests for half open connections

tests/manual-tests/half-open-close-server/server.py

@@ -0,0 +1,15 @@
+import socket
+
+with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as s:
+    s.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
+    s.bind(('0.0.0.0', 1337))
+    s.listen()
+    conn, addr = s.accept()
+    with conn:
+        conn.sendall('I am closing the write end, but I can still receive data'.encode())
+        conn.shutdown(socket.SHUT_WR)
+        while True:
+            data = conn.recv(1024)
+            if not data:
+                break
+            print(data.decode())