Fixed an issue with the libssh2_poll_channel_read function not

reading both normal and extended data when a non-zero value
is passed in as the 2nd parameter. This now matches the functionallity
described in the documentation.

src/session.c

@@ -1189,14 +1189,15 @@ libssh2_poll_channel_read(LIBSSH2_CHANNEL * channel, int extended)
     LIBSSH2_SESSION *session = channel->session;
     LIBSSH2_PACKET *packet = session->packets.head;
 
-    while (packet) {
-        if (((packet->data[0] == SSH_MSG_CHANNEL_DATA) && (extended == 0) &&
-             (channel->local.id == libssh2_ntohu32(packet->data + 1))) ||
-            ((packet->data[0] == SSH_MSG_CHANNEL_EXTENDED_DATA)
-             && (extended != 0)
-             && (channel->local.id == libssh2_ntohu32(packet->data + 1)))) {
-            /* Found data waiting to be read */
-            return 1;
+    while (packet) 
+	{
+		if ( channel->local.id == libssh2_ntohu32(packet->data + 1)) {
+			if ( extended == 1 &&
+				(packet->data[0] == SSH_MSG_CHANNEL_EXTENDED_DATA || packet->data[0] == SSH_MSG_CHANNEL_DATA ))
+				return 1;
+			else if ( extended == 0 && packet->data[0] == SSH_MSG_CHANNEL_DATA)
+				return 1;
+			//else - no data of any type is ready to be read
         }
         packet = packet->next;
     }