Fix checks for socket values, 0 is a legal value.

To make this work, we also have to initialize sockets
to a default value of -1.

Also close a client listen socket if it's open.
Signed-off-by: Christian Beier <dontmind@freeshell.org>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>

libvncclient/listen.c

@@ -127,7 +127,7 @@ listenForIncomingConnectionsNoFork(rfbClient* client, int timeout)
 
   client->listenSpecified = TRUE;
 
-  if (! client->listenSock)
+  if (client->listenSock < 0)
     {
       client->listenSock = ListenAtTcpPort(client->listenPort);
 

libvncclient/rfbproto.c

@@ -388,7 +388,7 @@ ConnectToRFBServer(rfbClient* client,const char *hostname, int port)
       fclose(rec->file);
       return FALSE;
     }
-    client->sock = 0;
+    client->sock = -1;
     return TRUE;
   }
 

libvncclient/vncviewer.c

@@ -190,7 +190,8 @@ rfbClient* rfbGetClient(int bitsPerSample,int samplesPerPixel,
 #ifdef LIBVNCSERVER_WITH_CLIENT_TLS
   client->tlsSession = NULL;
 #endif
-
+  client->sock = -1;
+  client->listenSock = -1;
   return client;
 }
 
@@ -334,8 +335,10 @@ void rfbClientCleanup(rfbClient* client) {
 #endif
 
   FreeTLS(client);
-  if (client->sock > 0)
+  if (client->sock >= 0)
     close(client->sock);
+  if (client->listenSock >= 0)
+    close(client->listenSock);
   free(client->desktopName);
   free(client->serverHost);
   free(client);

libvncserver/rfbserver.c

@@ -485,7 +485,7 @@ rfbClientConnectionGone(rfbClientPtr cl)
     if (cl->next)
         cl->next->prev = cl->prev;
 
-    if(cl->sock>0)
+    if(cl->sock>=0)
 	close(cl->sock);
 
     if (cl->scaledScreen!=NULL)