Fixed select not reporting received FIN as 'readable' in certain rare cases (bug #43779: select(), close(), and TCP retransmission error)

CHANGELOG

@@ -6,10 +6,6 @@ HISTORY
 
   ++ New features:
 
-  2015-02-17: Sylvain Rochet
-  * Large PPP rework, moved out low level protocols code (PPPoS, PPPoE, PPPoL2TP)
-    from PPP core code, making everything simpler.
-
   2015-02-16: Claudius Zingerli, Sergio Caprile
   * opt.h, dhcp.h/.c: patch #8361 "Add support for NTP option in DHCP"
 
@@ -190,6 +186,10 @@ HISTORY
 
   ++ Bugfixes:
 
+  2015-02-18: Simon Goldschmidt
+  * sockets.c: Fixed select not reporting received FIN as 'readable' in certain
+    rare cases (bug #43779: select(), close(), and TCP retransmission error)
+
   2015-02-17: Simon Goldschmidt
   * err.h, sockets.c, api_msg.c: fixed bug #38853 "connect() use a wrong errno":
     return ERR_ALREADY/EALRADY during connect, ERR_ISCONN/EISCONN when already

src/api/sockets.c

@@ -730,6 +730,10 @@ lwip_recvfrom(int s, void *mem, size_t len, int flags,
         if (off > 0) {
           /* update receive window */
           netconn_recved(sock->conn, (u32_t)off);
+          if (err == ERR_CLSD) {
+            /* closed but already received data, ensure select gets the FIN, too */
+            event_callback(sock->conn, NETCONN_EVT_RCVPLUS, 0);
+          }
           /* already received data, return that */
           sock_set_errno(sock, 0);
           return off;