Re: Strange Problems w/ gnome_error_dialog

[Eric Mader <mader jtcsv com>]

Owen Taylor wrote:

> On Fri, 2003-10-31 at 12:05, Eric Mader wrote:
>
> > Hello,
> >
> > I use the following simple method to issue error dialogs in the Gnome 
> > version of a cross-platform application:
> >
> > void GnomeGUISupport::postErrorMessage(const char *message, const char 
> > *title)
> > {
> >   gchar *s;
> >   GtkWidget *error;
> >
> >   s = g_strconcat(title, ":\n", message, NULL);
> >   error = gnome_error_dialog(s);
> >   gtk_widget_show(error);
> >   g_free(s);
> > }
> >
> > Sometimes when this method is called I see the following error message 
> > on the console:
> >
> > Gtk-CRITICAL **: file gtkwidget.c: line 1554 (gtk_widget_show_all): 
> > assertion 'widget != NULL' failed.
>
>
> I'd run with --g-fatal-warnings and get a backtrace. Nothing above looks
> suspicious.

Right. The problems turned out to be with the error handling in the 
application. In some failure cases it would try to use a NULL top-level 
widget, which is the reason for assertion failure.

In one particular failure case, the application would go into a (semi-) 
infinite loop, which explains why it would go into the weeds for several 
minutes. (in the loop it was adding items to a growable array. I assume 
that at some point it ran out of resources and the Kernel killed it... 
*before* it got to the main loop, so the dialog never displayed...)

> Regards,
>                                                 Owen

Regards,
Eric

> (This looks like GNOME-1.2, so basically off-topic for this list in 
> point of fact; if you were using GTK+-2.x, GtkMessageDialog provides
> a replacement for gnome_error_dialog()...)

My RedHat9 system doesn't seem to have GTK-2.* installed :-( I wonder if 
it didn't install it because I upgraded a RH7.3 system...

In any case, the application is the ICU LayoutEngine sample, and it 
needs to run on our supported RedHat platforms, which include RH 6 and 
7, so I probably need to stick w/ GNOME-1.2.

BTW: When I checked the web for information about gnome_error_dialog, it 
was marked as deprecated, but the note didn't say what to use instead. 
For deprecated functions, it's a good idea to say what should be used 
instead.