stream/async: fix session setup issues

For these 2 cases:

1. Missing SYN:
-> syn <= missing
<- syn/ack
-> ack
-> data

2. Missing SYN and 3whs ACK:
-> syn <= missing
<- syn/ack
-> ack <= missing
-> data

Fix session pickup. The next_win settings weren't correctly set, so that
packets were rejected.

Bug 1190.

src/stream-tcp.c

@@ -850,6 +850,8 @@ static int StreamTcpPacketStateNone(ThreadVars *tv, Packet *p,
         ssn->client.last_ack = TCP_GET_ACK(p);
         ssn->server.last_ack = TCP_GET_SEQ(p);
 
+        ssn->server.next_win = ssn->server.last_ack + ssn->server.window;
+
         /** If the client has a wscale option the server had it too,
          *  so set the wscale for the server to max. Otherwise none
          *  will have the wscale opt just like it should. */
@@ -1768,7 +1770,8 @@ static int StreamTcpPacketStateSynRecv(ThreadVars *tv, Packet *p,
             ssn->server.next_win = ssn->server.last_ack + ssn->server.window;
 
             if (ssn->flags & STREAMTCP_FLAG_MIDSTREAM) {
-                ssn->client.window = TCP_GET_WINDOW(p);
+                ssn->client.window = TCP_GET_WINDOW(p) << ssn->client.wscale;
+                ssn->client.next_win = ssn->client.last_ack + ssn->client.window;
                 ssn->server.next_win = ssn->server.last_ack +
                     ssn->server.window;
                 /* window scaling for midstream pickups, we can't do much