[gnome-builder] plugins/c-pack: be tolerant of calls past end of list

[Christian Hergert <chergert src gnome org>]

commit 2637417af692ff013ddab805f92e46a22cb1c240
Author: Christian Hergert <chergert redhat com>
Date:   Tue Oct 11 11:36:23 2022 -0500

    plugins/c-pack: be tolerant of calls past end of list
    
    GTK can do this to discover the end of a list model and we need to be
    more tolerant of that.
    
    Fixes #1860

 src/plugins/c-pack/cpack-completion-results.c | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)
---
diff --git a/src/plugins/c-pack/cpack-completion-results.c b/src/plugins/c-pack/cpack-completion-results.c
index 50cdd5e8d..39200292e 100644
--- a/src/plugins/c-pack/cpack-completion-results.c
+++ b/src/plugins/c-pack/cpack-completion-results.c
@@ -106,15 +106,14 @@ static gpointer
 cpack_completion_results_get_item (GListModel *model,
                                    guint       position)
 {
-  CpackCompletionResults *self = (CpackCompletionResults *)model;
-  const Item *item;
+  CpackCompletionResults *self = CPACK_COMPLETION_RESULTS (model);
 
   g_assert (CPACK_IS_COMPLETION_RESULTS (self));
-  g_assert (position < self->items->len);
 
-  item = &g_array_index (self->items, Item, position);
+  if (position >= self->items->len)
+    return NULL;
 
-  return cpack_completion_item_new (item->word);
+  return cpack_completion_item_new (g_array_index (self->items, Item, position).word);
 }
 
 static void