diff --git a/gtk/gtklistlistmodel.c b/gtk/gtklistlistmodel.c
index 9644b896c5..a35493b03b 100644
--- a/gtk/gtklistlistmodel.c
+++ b/gtk/gtklistlistmodel.c
@@ -41,6 +41,9 @@ struct _GtkListListModel
   gpointer (* get_item) (gpointer, gpointer);
   gpointer data;
   GDestroyNotify notify;
+
+  guint cache_pos;
+  gpointer cache_item;
 };
 
 struct _GtkListListModelClass
@@ -72,6 +75,18 @@ gtk_list_list_model_get_n_items (GListModel *list)
   return self->n_items;
 }
 
+static gboolean
+gtk_list_list_model_cache_is_valid (GtkListListModel *self)
+{
+  return self->cache_item != NULL;
+}
+
+static void
+gtk_list_list_model_invalidate_cache (GtkListListModel *self)
+{
+  self->cache_item = NULL;
+}
+
 static gpointer
 gtk_list_list_model_get_item (GListModel *list,
                               guint       position)
@@ -79,31 +94,50 @@ gtk_list_list_model_get_item (GListModel *list,
   GtkListListModel *self = GTK_LIST_LIST_MODEL (list);
   gpointer result;
   guint i;
+  guint start, end;
 
   if (position >= self->n_items)
-    {
-      return NULL;
-    }
-  else if (self->get_last &&
-           position >= self->n_items / 2)
-    {
-      result = self->get_last (self->data);
+    return NULL;
 
-      for (i = self->n_items - 1; i > position; i--)
+  start = 0;
+  end = self->n_items;
+  if (gtk_list_list_model_cache_is_valid (self))
+    {
+      if (self->cache_pos <= position)
+        start = self->cache_pos;
+      else
+        end = self->cache_pos;
+    }
+
+  if (self->get_last &&
+      position > (start + end) / 2)
+    {
+      if (end == self->cache_pos && gtk_list_list_model_cache_is_valid (self))
+        result = self->get_previous (self->cache_item, self->data);
+      else
+        result = self->get_last (self->data);
+
+      for (i = end - 1; i > position; i--)
         {
           result = self->get_previous (result, self->data);
         }
     }
   else
     {
-      result = self->get_first (self->data);
+      if (start == self->cache_pos && gtk_list_list_model_cache_is_valid (self))
+        result = self->cache_item;
+      else
+        result = self->get_first (self->data);
 
-      for (i = 0; i < position; i++)
+      for (i = start; i < position; i++)
         {
           result = self->get_next (result, self->data);
         }
     }
 
+  self->cache_item = result;
+  self->cache_pos = position;
+
   return self->get_item (result, self->data);
 }
 
@@ -275,7 +309,9 @@ gtk_list_list_model_item_added_at (GtkListListModel *self,
   g_return_if_fail (GTK_IS_LIST_LIST_MODEL (self));
   g_return_if_fail (position <= self->n_items);
 
-  self->n_items += 1;
+  self->n_items++;
+  if (position <= self->cache_pos)
+    self->cache_pos++;
 
   g_list_model_items_changed (G_LIST_MODEL (self), position, 0, 1);
   g_object_notify_by_pspec (G_OBJECT (self), properties[PROP_N_ITEMS]);
@@ -327,6 +363,12 @@ gtk_list_list_model_item_moved (GtkListListModel *self,
 
   min = MIN (position, previous_position);
   max = MAX (position, previous_position) + 1;
+
+  if (self->cache_item == item)
+    self->cache_pos = position;
+  else if (self->cache_pos >= min && self->cache_pos < max)
+    self->cache_pos += (self->cache_pos > position ? 1 : -1);
+
   g_list_model_items_changed (G_LIST_MODEL (self), min, max - min, max - min);
 }
 
@@ -338,6 +380,10 @@ gtk_list_list_model_item_removed_at (GtkListListModel *self,
   g_return_if_fail (position < self->n_items);
 
   self->n_items -= 1;
+  if (position == self->cache_pos)
+    gtk_list_list_model_invalidate_cache (self);
+  else if (position < self->cache_pos)
+    self->cache_pos--;
 
   g_list_model_items_changed (G_LIST_MODEL (self), position, 1, 0);
   g_object_notify_by_pspec (G_OBJECT (self), properties[PROP_N_ITEMS]);
@@ -358,6 +404,8 @@ gtk_list_list_model_clear (GtkListListModel *self)
   self->n_items = 0;
   self->notify = NULL;
 
+  gtk_list_list_model_invalidate_cache (self);
+
   if (n_items > 0)
     {
       g_list_model_items_changed (G_LIST_MODEL (self), 0, n_items, 0);
diff --git a/gtk/inspector/action-editor.c b/gtk/inspector/action-editor.c
index ba838fbaf7..2065a48fd7 100644
--- a/gtk/inspector/action-editor.c
+++ b/gtk/inspector/action-editor.c
@@ -38,6 +38,7 @@ struct _GtkInspectorActionEditor
   gboolean enabled;
   const GVariantType *parameter_type;
   GVariantType *state_type;
+  GVariant *state;
   GtkWidget *activate_button;
   GtkWidget *parameter_entry;
   GtkWidget *state_entry;
@@ -101,6 +102,11 @@ state_changed (GtkWidget *editor,
     return;
 
   g_variant_ref_sink (value);
+  if (g_variant_equal (value, r->state))
+    {
+      g_variant_unref (value);
+      return;
+    }
 
   if (G_IS_ACTION_GROUP (r->owner))
     g_action_group_change_action_state (G_ACTION_GROUP (r->owner), r->name, value);
@@ -147,35 +153,35 @@ gtk_inspector_action_editor_init (GtkInspectorActionEditor *r)
 static void
 update_widgets (GtkInspectorActionEditor *r)
 {
-  GVariant *state;
+  g_clear_pointer (&r->state, g_variant_unref);
 
   if (G_IS_ACTION_GROUP (r->owner))
     {
       if (!g_action_group_query_action (G_ACTION_GROUP (r->owner), r->name,
                                         &r->enabled, &r->parameter_type, NULL, NULL,
-                                        &state))
+                                        &r->state))
         {
           r->enabled = FALSE;
           r->parameter_type = NULL;
-          state = NULL;
+          r->state = NULL;
         }
     }
   else if (GTK_IS_ACTION_MUXER (r->owner))
     {
       if (!gtk_action_muxer_query_action (GTK_ACTION_MUXER (r->owner), r->name,
                                           &r->enabled, &r->parameter_type, NULL, NULL,
-                                          &state))
+                                          &r->state))
         {
           r->enabled = FALSE;
           r->parameter_type = NULL;
-          state = NULL;
+          r->state = NULL;
         }
     }
   else
     {
       r->enabled = FALSE;
       r->parameter_type = NULL;
-      state = NULL;
+      r->state = NULL;
     }
 
   gtk_widget_set_sensitive (r->activate_button, r->enabled);
@@ -184,15 +190,13 @@ update_widgets (GtkInspectorActionEditor *r)
   if (r->parameter_type)
     gtk_inspector_variant_editor_set_type (r->parameter_entry, r->parameter_type);
 
-  gtk_widget_set_visible (r->state_editor, state != NULL);
-  if (state)
+  gtk_widget_set_visible (r->state_editor, r->state != NULL);
+  if (r->state)
     {
       if (r->state_type)
         g_variant_type_free (r->state_type);
-      r->state_type = g_variant_type_copy (g_variant_get_type (state));
-      gtk_inspector_variant_editor_set_value (r->state_entry, state);
-
-      g_variant_unref (state);
+      r->state_type = g_variant_type_copy (g_variant_get_type (r->state));
+      gtk_inspector_variant_editor_set_value (r->state_entry, r->state);
     }
 }
 
@@ -207,6 +211,7 @@ dispose (GObject *object)
 
   g_clear_pointer (&r->name, g_free);
   g_clear_pointer (&r->state_type, g_variant_type_free);
+  g_clear_pointer (&r->state, g_variant_unref);
 
   G_OBJECT_CLASS (gtk_inspector_action_editor_parent_class)->dispose (object);
 }
diff --git a/testsuite/gtk/listlistmodel.c b/testsuite/gtk/listlistmodel.c
index 7d1f25aa35..d1898e23f8 100644
--- a/testsuite/gtk/listlistmodel.c
+++ b/testsuite/gtk/listlistmodel.c
@@ -71,7 +71,7 @@ free_changes (gpointer data)
 }
 
 static void
-test_list_list_model (void)
+test_change (void)
 {
   GtkWidget *box;
   GListModel *model;
@@ -111,6 +111,87 @@ test_list_list_model (void)
   g_object_unref (box);
 }
 
+static void
+test_exhaustive (void)
+{
+  GtkBox *box;
+  GListModel *model, *compare;
+  guint i;
+
+  box = GTK_BOX (gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 0));
+  g_object_ref_sink (box);
+
+  model = gtk_widget_observe_children (GTK_WIDGET (box));
+  compare = G_LIST_MODEL (g_list_store_new (GTK_TYPE_WIDGET));
+
+  for (i = 0; i < 500; i++)
+    {
+      switch (g_test_rand_int_range (0, 4))
+      {
+        case 0:
+          /* compare */
+          g_assert_cmpint (g_list_model_get_n_items (model), ==, g_list_model_get_n_items (compare));
+          if (g_list_model_get_n_items (compare) > 0)
+            {
+              guint n = g_list_model_get_n_items (compare);
+              guint step = n == 1 ? 1 : g_test_rand_int_range (1, n);
+              guint j = 0;
+              do
+                {
+                  gpointer o1 = g_list_model_get_item (model, j);
+                  gpointer o2 = g_list_model_get_item (compare, j);
+                  g_assert_cmphex (GPOINTER_TO_SIZE (o1), ==, GPOINTER_TO_SIZE (o2));
+                  g_object_unref (o1);
+                  g_object_unref (o2);
+                  j = (j + step) % n;
+                }
+              while (j != 0);
+            }
+          break;
+
+        case 1:
+          /* remove a widget */
+          if (g_list_model_get_n_items (compare) > 0)
+            {
+              guint position = g_test_rand_int_range (0, g_list_model_get_n_items (compare));
+              GtkWidget *child = g_list_model_get_item (compare, position);
+              gtk_box_remove (box, child);
+              g_list_store_remove (G_LIST_STORE (compare), position);
+              g_object_unref (child);
+            }
+          break;
+
+        case 2:
+          /* add a widget */
+          {
+            guint position = g_test_rand_int_range (0, g_list_model_get_n_items (compare) + 1);
+            GtkWidget *child = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 0);
+            GtkWidget *sibling;
+            if (position == 0)
+              sibling = NULL;
+            else
+              sibling = g_list_model_get_item (compare, position - 1);
+            gtk_box_insert_child_after (box, child, sibling);
+            g_list_store_insert (G_LIST_STORE (compare), position, child);
+            g_clear_object (&sibling);
+          }
+          break;
+
+        case 3:
+          /* move a widget (FIXME) */
+          break;
+
+        default:
+          g_assert_not_reached ();
+          break;
+      }
+    }
+
+  g_object_unref (compare);
+  g_object_unref (box);
+  g_object_unref (model);
+}
+
 int
 main (int argc, char *argv[])
 {
@@ -120,7 +201,8 @@ main (int argc, char *argv[])
 
   changes_quark = g_quark_from_static_string ("What did I see? Can I believe what I saw?");
 
-  g_test_add_func ("/listlistmodel/change", test_list_list_model);
+  g_test_add_func ("/listlistmodel/change", test_change);
+  g_test_add_func ("/listlistmodel/exhaustive", test_exhaustive);
 
   return g_test_run ();
 }