Re: Programmer's criticism of GTK2

[Jonathan Blandford <jrb redhat com>]

Maxim Koshelev <max krascoal ru> writes:

> yeah, I've attached slightly changed list_store.c from gtk-demo part
> of gtk2.
> Just replace list_store.c by this file and recompile demo.
> Four clicks will remove a row. Look to stderr...
> if you change
>  gtk_list_store_remove (GTK_LIST_STORE (model), d->iter);
> by
>  gtk_list_store_remove (GTK_LIST_STORE (model), &iter);
> you'll get another warning :-)

You do:

  if (click_counter==4){
    gtk_list_store_remove (GTK_LIST_STORE (model), d->iter);
  }
  ...

  /* set new value */
  gtk_list_store_set (GTK_LIST_STORE (model), &iter, COLUMN_FIXED,  fixed, -1);

And are getting a warning here.  This is because d->iter and &iter point
to the same row.  (You can put in something like:

  path = gtk_tree_model_get_path (model, d->iter);
  g_print ("path1:%s\n", gtk_tree_path_to_string (path));
  path = gtk_tree_model_get_path (model, &iter);
  g_print ("path2:%s\n", gtk_tree_path_to_string (path));

if you don't believe me[1]).  After you remove d->iter, &iter is
pointing to a dead row, and cannot be used, hence your warnings[2].
While the row is valid, you are using both d->iter, and &iter fine.

A thought occurred to me, recently.  Which version of GTK+ are you
using?  There was a bug fixed about a month and a half ago where the
stamp was being changed in lists.  Are you using GTK+ 2.0, or at least
1.3.15?

Thanks,
-Jonathan


[1] I know this leaks.  Please don't anyone copy this code for real use.
[2] And no, I don't want to walk through the free list to check for
    invalid iters in VALID_ITER.