This fix addresses bug# 2141548. Channel reads would fail despite

libssh2_poll() detecting that there was data ready to be read on
the socket. This is seen when small amounts of data are ready to
be read, typically 1-4 chars worth.

src/channel.c

@@ -1521,7 +1521,8 @@ libssh2_channel_read_ex(LIBSSH2_CHANNEL * channel, int stream_id, char *buf,
             channel->read_packet = session->packets.head;
         }
 
-        if (rc < 0) {
+		//We didn't read any data from the socket and no packets are waiting to be read
+		if (rc < 0) && (! channel->read_packet)) {
 			if (rc != PACKET_EAGAIN) {
 				channel->read_state = libssh2_NB_state_idle;
 			}