treelistmodel: Be safer during collapsing

While we are collapsing a subtree, some signal handlers may not be
disconnected while we are doing this. By adding this check and not
giving those nodes no longer access to the model, we can stop it from
modifying it while we are trying to collapse stuff.

Fixes some crashes in gnome-builder.

diff --git a/gtk/gtktreelistmodel.c b/gtk/gtktreelistmodel.c
index 1e55323c0a4e548bcde5389e72928eee1438c0c9..81b4319c150e52b0313845ff12aeebee7c29eb77 100644 (file)
--- a/gtk/gtktreelistmodel.c
+++ b/gtk/gtktreelistmodel.c
@@ -101,8 +101,15 @@ static GParamSpec *properties[NUM_PROPERTIES] = { NULL, };
 static GtkTreeListModel *
 tree_node_get_tree_list_model (TreeNode *node)
 {
-  for (; !node->is_root; node = node->parent)
-    { }
+  if (node->is_root)
+    return node->list;
+
+  for (node = node->parent; !node->is_root; node = node->parent)
+    {
+      /* This can happen during collapsing of a parent node */
+      if (node->children == NULL)
+        return NULL;
+    }
 
   return node->list;
 }
@@ -316,6 +323,9 @@ gtk_tree_list_model_items_changed_cb (GListModel *model,
   guint i, tree_position, tree_removed, tree_added, n_local;
 
   self = tree_node_get_tree_list_model (node);
+  if (self == NULL)
+    return;
+
   n_local = g_list_model_get_n_items (model) - added + removed;
 
   if (position < n_local)
@@ -1180,6 +1190,8 @@ gtk_tree_list_row_set_expanded (GtkTreeListRow *self,
     return;
 
   list = tree_node_get_tree_list_model (self->node);
+  if (list == NULL)
+    return;
 
   if (expanded)
     {
@@ -1255,6 +1267,9 @@ gtk_tree_list_row_is_expandable (GtkTreeListRow *self)
     return TRUE;
 
   list = tree_node_get_tree_list_model (self->node);
+  if (list == NULL)
+    return FALSE;
+
   model = tree_node_create_model (list, self->node);
   if (model)
     {