Re: Seg Fault on NULL strlen

[Neil Hodge <neh attbi com>]

Steve:

On Sat, 2002-12-28 at 17:38, Steve & Patti Getzinger wrote:
> > void
> > on_entry1_changed                (GtkEditable     *editable,
> >                                         gpointer         user_data)
> > {
> >   if(strlen(gtk_editable_get_chars(GTK_EDITABLE(entry1),0,-1)) > 7)
> >         {
> >                   
> > if(strlen(gtk_editable_get_chars(GTK_EDITABLE(entry2),0,-1)) > 0)
>
> >                         {
> >                         gtk_widget_set_sensitive (button1, TRUE);
> >                         }
> >         }else{
> >                 gtk_widget_set_sensitive (button1, FALSE);
> >         }
> > }
>
> With this config it seg faults with:
>
> > (gdiald:16598): GLib-GObject-WARNING **: invalid cast from (NULL) 
> > pointer to `GtkEditable'
> >
> > (gdiald:16598): Gtk-CRITICAL **: file gtkeditable.c: line 125 
> > (gtk_editable_get_chars): assertion `GTK_IS_EDITABLE (editable)' failed
> > Segmentation fault
>
>
> I am assuming strlen returns NULL if there has been no entry made in 
> entry2. How do I get around this one?

Switch your if statement around.  Drop the strlens, and check for NULL
directly (i.e., strlen=0), and if true, set_sensitive FALSE, otherwise
(i.e., strlen>0), set_sensitive TRUE.

Neil