Pourquoi ajouter les enfants d'un noeud à la fin de la liste (des enfants) ?

hot.c

@@ -12,20 +12,39 @@
 //  https://docs.gtk.org/gtk4/class.Widget.html#height-for-width-geometry-management
 //  GTK_ORIENTATION_VERTICAL       GTK_ORIENTATION_HORIZONTAL
 
-
 static struct TreeNode_t {gchar *text; struct TreeNode_t *child, *next;};
-static void add_child_node (struct TreeNode_t *parent, struct TreeNode_t *child);
+
 static struct TreeNode_t *create_user_tree_node (const gchar* text){
     struct TreeNode_t *node = g_malloc0 (sizeof(struct TreeNode_t));
     node->text = g_strdup (text);
-    node->child = NULL;       //  if (0) printf("create_user_tree_node  %s\n", text);
+    node->child = NULL;
+    printf("create_user_tree_node  %s   ", text); if (text == "root") printf("\n");
     return node;
 }
 
-static void create_a_complex_useless_and_expensive_tree (struct TreeNode_t *tree_root){
-/*    struct TreeNode_t *move_random = create_user_tree_node("move random");  add_child_node(tree_root, move_random);
-    struct TreeNode_t *move_determ = create_user_tree_node("move determ");  add_child_node(tree_root, move_determ);
-    struct TreeNode_t *transport   = create_user_tree_node("transport");    add_child_node(tree_root, transport);*/
+static void add_child_node (struct TreeNode_t *parent, struct TreeNode_t *child){
+    if (parent->child && parent->child != child) {
+        parent->child = child;
+        printf("add_child_node (%s, %s) \n", parent->text, child->text);
+           } else printf("add_child_node (%s, %s) else \n", parent->text, child->text);
+}
+
+static void create_a_simple_tree (struct TreeNode_t *tree_root){
+
+    struct TreeNode_t *a    = create_user_tree_node("a");  add_child_node(tree_root, a);
+    struct TreeNode_t *b    = create_user_tree_node("b");  add_child_node(tree_root, b);
+
+    struct TreeNode_t *aa   = create_user_tree_node("aa");   add_child_node(a, aa);
+    struct TreeNode_t *aaa  = create_user_tree_node("aaa");  add_child_node(aa, aaa);
+
+    struct TreeNode_t *bb   = create_user_tree_node("bb");   add_child_node(b, bb);
+    struct TreeNode_t *bbb  = create_user_tree_node("bbb");  add_child_node(bb, bbb);
+}
+
+static void create_a_hazardous_complex_useless_and_expensive_tree (struct TreeNode_t *tree_root){
+//    struct TreeNode_t *move_random = create_user_tree_node("move random");  add_child_node(tree_root, move_random);
+//    struct TreeNode_t *move_determ = create_user_tree_node("move determ");  add_child_node(tree_root, move_determ);
+//    struct TreeNode_t *transport   = create_user_tree_node("transport");    add_child_node(tree_root, transport);
     struct TreeNode_t *transform   = create_user_tree_node("transform");    add_child_node(tree_root, transform);
     struct TreeNode_t *regulate    = create_user_tree_node("regulate");     add_child_node(tree_root, regulate);
 /*    struct TreeNode_t *isole       = create_user_tree_node("isolated object"); add_child_node(move_random, isole);
@@ -113,17 +132,10 @@ GListModel* get_user_tree_model (GObject *item, gpointer root){
     return get_user_tree_model_child (cur);
 }
 
-static void add_child_node (struct TreeNode_t *parent, struct TreeNode_t *child){
-    if (parent->child) {
-        struct TreeNode_t *cur = parent->child;
-        while (cur && cur->next) {cur = cur->next;}
-        cur->next = child;
-    } else parent->child = child;
-}
-
 GtkScrolledWindow *get_user_rules_tree (){
     struct TreeNode_t *tree_root   = create_user_tree_node("root");
-    create_a_complex_useless_and_expensive_tree (tree_root);
+//  create_a_hazardous_complex_useless_and_expensive_tree (tree_root);
+    create_a_simple_tree (tree_root);
 
     GtkStringList *model = gtk_string_list_new(NULL);
     gtk_string_list_append (model, tree_root->text);
@@ -134,7 +146,7 @@ GtkScrolledWindow *get_user_rules_tree (){
     GtkTreeListModel *tree_model = gtk_tree_list_model_new(
         G_LIST_MODEL (model),
         FALSE, // Passthrough - False in actual usage with dynamic children retrieval
-        TRUE, //  FALSE, // autoexpand
+        FALSE, // autoexpand   TRUE, //
         (GtkTreeListModelCreateModelFunc) &get_user_tree_model,
         tree_root,
         NULL // (GDestroyNotify) free_user_tree_node