fix defect 3786

perl-xCAT/xCAT/Client.pm

@@ -231,6 +231,16 @@ if (ref($request) eq 'HASH') { # the request is an array, not pure XML
 		 Timeout => 0,
 		);
   }
+  unless ($client) {
+     print "Unable to open socket connection to xcatd daemon on $xcathost.\n";
+     print "Verify that the xcatd daemon is running and that your SSL setup is correct.\n";
+     if ($@ =~ /SSL Timeout/) {
+        die "Connection failure: SSL Timeout or incorrect certificates in ~/.xcat";
+     } else {
+        die "Connection failure: $@"
+     }
+  }
+
   my $msg;
   if (ref($request) eq 'HASH') { # the request is an array, not pure XML
     $msg=XMLout($request,RootName=>'xcatrequest',NoAttr=>1,KeyAttr=>[]);