[vino] Improve handling of name resolution failure

[David King <davidk src gnome org>]

commit bdd14508f9ea46372fcef93e17a9c14bcb8b4c83
Author: Dimitri Tarassenko <dtarassenko gmail com>
Date:   Fri Aug 28 17:02:15 2015 +0100

    Improve handling of name resolution failure
    
    Ensure that the host string for a client is always filled with a valid
    string, by calling getnameinfo() a second time (ensuring a numeric host
    is returned) if the first call fails.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=754194

 server/libvncserver/rfbserver.c |   12 ++++++------
 1 files changed, 6 insertions(+), 6 deletions(-)
---
diff --git a/server/libvncserver/rfbserver.c b/server/libvncserver/rfbserver.c
index 1295219..0a60fb2 100644
--- a/server/libvncserver/rfbserver.c
+++ b/server/libvncserver/rfbserver.c
@@ -150,7 +150,7 @@ rfbNewClient(rfbScreenInfoPtr rfbScreen,
     struct sockaddr_storage addr;
     socklen_t addrlen = sizeof(addr);
     int i;
-    char host[NI_MAXHOST];
+    char host[NI_MAXHOST] = "(unresolved)";
     const char *prt = "unknown";
 
     cl = (rfbClientPtr)calloc(sizeof(rfbClientRec),1);
@@ -166,11 +166,11 @@ rfbNewClient(rfbScreenInfoPtr rfbScreen,
 
       getpeername(sock, (struct sockaddr *)&addr, &addrlen);
 
-      getnameinfo((struct sockaddr *)&addr,
-                  addrlen,
-                  host, sizeof(host),
-                  NULL, 0,
-                  0);
+      if (getnameinfo((struct sockaddr *)&addr, addrlen,
+                      host, sizeof(host), NULL, 0, 0)) {
+        getnameinfo((struct sockaddr *)&addr, addrlen,
+                    host, sizeof(host), NULL, 0, NI_NUMERICHOST);
+      }
 
       cl->host = strdup(host);