Wb and xtt bugfix for non ISO8859-1 chars

wb/lib/wb/gtk/wb_wtt_gtk.cpp

@@ -1491,6 +1491,11 @@ void WttGtk::valchanged_cmd_input( GtkWidget *w, gpointer data)
   text = g_convert( textutf8, -1, "ISO8859-1", "UTF-8", NULL, NULL, NULL);
   g_free( textutf8);
 
+  if ( !text) {
+    wtt->wnav->wow->DisplayError( "Input error", "Invalid character");
+    return;
+  }
+
   if ( wtt->input_open) {
     switch( wtt->input_mode)  {
     case wtt_eInputMode_Attribute:

xtt/exe/rt_xtt/gtk/rt_xtt_gtk.cpp

@@ -631,6 +631,16 @@ void XttGtk::valchanged_cmd_input( GtkWidget *w, gpointer data)
   text = g_convert( textutf8, -1, "ISO8859-1", "UTF-8", NULL, NULL, NULL);
   g_free( textutf8);
 
+  if ( !text) {
+    g_object_set( w, "visible", FALSE, NULL);
+    xtt->set_prompt( "");
+    xtt->input_open = 0;
+    xtt->command_open = 0;
+    xtt->xnav->set_inputfocus();
+    xtt->message( 'E', "Input error, invalid character");
+    return;
+  }
+
   if ( xtt->input_open) {
     sts = xtt->xnav->set_attr_value( text);
     g_object_set( w, "visible", FALSE, NULL);