Index: vws
==================================================================
--- vws
+++ vws
@@ -48,10 +48,12 @@
         dummy_greeting = sock.recv(1024)
     return sock
 
 def send_command(sock, command):
     """ Sends monitor command to given socket and returns answer """
+    if sock is None:
+        raise RuntimeError("None socket is passed to send_command")
     fcntl.flock(sock, fcntl.LOCK_EX)
     try:
         # There can be stray (qemu) prompt in the socket. Try to drain
         # it
         try:
@@ -185,11 +187,11 @@
     from config, if not so
     """
     f = open(filename, "r+")
     data = f.read()
     idx0 = data.find("-net bridge,br=")
-    if idx != -1:
+    if idx0 != -1:
         idx = data.find("=", idx0)
         idx += 1
         idx2 = data.find(" ", idx)
         bridgename = data[idx:idx2]
         if not bridgename in list_bridges():
@@ -252,18 +254,21 @@
         if snapshot_id is not None:
             arg = arg + " -loadvm " + snapshot_id
         # Check for correct brige name
         try:
             os.stat("monitor")
-        except OSError:
+        except FileNotFoundError:
             # We cannot find monitor socket. So this machine might be
             # never run on this host
             fix_bridge_name("start")
         os.system("./start%s" % arg)
         os.chdir(cwd)
         time.sleep(2)
         options.sock = connect_vm(options.dir)
+        if options.sock is None:
+            print("VM start failed", file=sys.stderr)
+            sys.exit(1)
         if snapshot_id:
             send_command(options.sock, "delvm " + snapshot_id)
     else:
         if options.snapshot or options.args or options.password:
             print("Cannot change qemu options. " +