socket polling / handle more error case such as hanged socket

ixwebsocket/IXSocket.cpp

@@ -54,11 +54,12 @@ namespace ix
         // to ::poll does fix that.
         //
         // However poll isn't as portable as select and has bugs on Windows, so we
-        // should write a shim to fallback to select on those platforms. See
+        // have a shim to fallback to select on those platforms. See
         // https://github.com/mpv-player/mpv/pull/5203/files for such a select wrapper.
         //
         nfds_t nfds = 1;
         struct pollfd fds[2];
+        memset(fds, 0 , sizeof(fds));
 
         fds[0].fd = sockfd;
         fds[0].events = (readyToRead) ? POLLIN : POLLOUT;
@@ -132,6 +133,10 @@ namespace ix
             }
 #endif
         }
+        else if (sockfd != -1 && (fds[0].revents & POLLERR || fds[0].revents & POLLHUP))
+        {
+            pollResult = PollResultType::Error;
+        }
 
         return pollResult;
     }