Re: Still problems with gtk_list_store_append

[Michael Unterkalmsteiner <miciu gmx de>]

On Mon, Mar 01, 2004 at 02:28:24PM +0100, Jesper Mørk wrote:
> Hi List
> 
> I didn't really resolve the problem the last time so i'm trying again in
> hope that someone can help me. Its damn frustrating that it wont work.
> 
> To summarize the problem. I'm trying to add som data to a list store. It
> works fine for the first rows but then suddenly it crashes with a
> segfault. As far as I can tell it crashes when calling
> gtk_list_store_append(). The data I'm trying to populate the list store
> with comes from a GList of a struct that looks like this:
> 
> typedef struct {
>   char * mid;
>   char * title;
>   char * director;
>   char * year;
>   char * genre;
>   char * language;
>   char * runtime;
>   char * imdb;
>   char * media;
>   char * mediasource;
>   char * mediaformat;
>   char * discnumber;
>   char * seen;
>   char * borrowed;
> } Movie;
> 
> My code for populating the list store is:
> 
> int repopulate_list(GtkWidget * widget, GtkListStore * model){
>   GtkTreeIter iter;
>   GList * movies = NULL;
>   GList * movie_element;
>   Movie * movie = NULL;
>   FILE * fptr;
>   int i = 0;
> 
>   printf("Clearing...\n");
>   /* Clear list for repopulation */
>   gtk_list_store_clear(model);
>     
>   printf("Open file for reading...\n");
>   /* Populate list store */
>   if(fopen(selected_filename, "r") != NULL){
>     movies = listMovies(selected_filename);
>   } else {
>     fptr = fopen(selected_filename, "w");
>     fprintf(fptr, "<?xml version=\"1.0\"?>\n");
>     fprintf(fptr, "<movies></movies>\n");
>   }
>   
>   printf("Get first...\n");
>   movie_element = g_list_first(movies);
>   while(movie_element != NULL){
> 
>     /* De reference list data */
>     movie = (Movie*)movie_element->data;
> 
>     /* Set values on list... */
>     printf("Appending...\n");
>     gtk_list_store_append(model, &iter);
>     printf("Set...\n");
>     gtk_list_store_set(model, &iter, 0, movie->mid, 1, movie->title, 2,
> movie->imdb, 3, movie->mediasource, 4, movie->mediaformat, 5,
> movie->borrowed, -1);
>     
>     /* Go to next element in list */
>     movie_element = g_list_next(movie_element);
>   }
> 
>   return 1;
> }

You must allocate memory for your struct. Look in your glib-doc for
g_new(), g_new0().

> 
> What is really strange is that when i start the program with an empty
> list everything is fine, and I can even add lines for a while without
> any troubles. But after it crashes with the segfault it wont event do
> the first few lines. Output from the program after the first initial
> segfault:

Typical symptoms of "wild pointers" are undefinable segfaults,
because they point *somewhere* in your memory.

hth, 

Michael