Consecutive gtk_list_store_set calls on the same iter

[Daniel Drake <dan reactivated net>]

Hi,

While recoding some non-working code (who knows what I was smoking when I 
wrote it..), I came across an issue which I'm not so sure about.

If you use gtk_list_store_set on an iter, then use gtk_list_store_set again on 
the same iter, you get an instant segfault on the second call.

== Begin code example ==

GtkTreeIter iter;

/* The following function calls work without problem */
gtk_list_store_append(liststore, &iter);
gtk_list_store_set(liststore, &iter,
	column1, value1,
	column2, value2,
	-1);

/* The next call causes instant segfault */
gtk_list_store_set(liststore, &iter,
	column3, value3,
	-1);

== End code example ==

Obviously it makes sense to combine the two calls into one, in which case, the 
problem is not present. In my situation, it wasn't quite as simple to do this, 
as inbetween the two calls to gtk_list_store_set I had multiple if conditions.

Is this behaviour expected? Should I file a bug? I would at least like to 
suggest that GTK produces a WARNING message in a scenario like this, rather 
than just segfaulting without a hint.

Daniel