Re: problem: gtk_image gives critical error

["David Necas (Yeti)" <yeti physics muni cz>]

On Tue, Apr 18, 2006 at 03:05:51AM -0700, Deependra Shekhawat wrote:
> Hello friends,
> This is my code:
>
> struct splash
> {
>       GtkWidget *splash_image;
> };
> void func1(void)
> {
>       GtkWidget *img;
>       struct splash p;

This structure is created on stack and exists only until the
function func1 exits.

>       img=gtk_image_new();
>       p.splash_image=img;     
>       
>       g_signal_connect(G_OBJECT(button1),
>                        "clicked",
>                        G_CALLBACK(on_butt_clicked),
>                        (gpointer) &p);

Therefore &p becomes invalid immediately after you pass it
to g_signal_connect().

> }
>
> void on_butt_clicked(GtkButton *button,gpointer data)
> {
>       struct splash *ptr;
>       ptr=(struct splash *)data;
>
>       //some code is here
>       
>       //following line gives error at execution time.
> gtk_image_set_from_pixbuf(GTK_IMAGE((GtkWidget*)ptr->splash_image),buffer);
> }
>
> Error is:
> (splash_screen:3549): Gtk-CRITICAL **: file
> gtkimage.c: line 772 (gtk_image_set_from_pixbuf):
>  assertion `GTK_IS_IMAGE (image)' failed

So, you are accessing some random piece of stack here.

Yeti


--
That's enough.