[gtk-vnc] Fix NULL dereference in debug logging on socket read error

[Daniel P. Berrange <dberrange src gnome org>]

commit 2ebe6faa07dbcecfca71fbe84e64d4994be8cc24
Author: Daniel P. Berrange <berrange redhat com>
Date:   Fri Dec 7 15:19:40 2012 +0000

    Fix NULL dereference in debug logging on socket read error

 src/vncconnection.c |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)
---
diff --git a/src/vncconnection.c b/src/vncconnection.c
index df514b3..ef55cb2 100644
--- a/src/vncconnection.c
+++ b/src/vncconnection.c
@@ -683,11 +683,12 @@ static int vnc_connection_read_wire(VncConnection *conn, void *data, size_t len)
                                NULL, &error);
         if (ret < 0) {
             if (error) {
+                VNC_DEBUG("Read error %s", error->message);
                 if (error->code == G_IO_ERROR_WOULD_BLOCK)
                     blocking = TRUE;
                 g_error_free(error);
             } else {
-                VNC_DEBUG("Read error %s", error->message);
+                VNC_DEBUG("Read error unknown");
             }
             ret = -1;
         }