[gtk: 1/2] gtk: Allow selection models to take null list model during construction

[Emmanuele Bassi <ebassi src gnome org>]

commit cd7748519391fabc7cd8ddc34783b6ad858ac5d1
Author: Jason Francis <jason@cycles.network>
Date:   Mon Mar 15 09:30:33 2021 -0400

    gtk: Allow selection models to take null list model during construction
    
    This brings it in line with the documentation, and with the respective
    set_model() functions.

 gtk/gtkmultiselection.c         |  2 +-
 gtk/gtknoselection.c            |  2 +-
 gtk/gtksingleselection.c        |  2 +-
 testsuite/gtk/multiselection.c  | 12 ++++++++++++
 testsuite/gtk/singleselection.c | 12 ++++++++++++
 5 files changed, 27 insertions(+), 3 deletions(-)
---
diff --git a/gtk/gtkmultiselection.c b/gtk/gtkmultiselection.c
index 2b60ab8302..3df394d1d1 100644
--- a/gtk/gtkmultiselection.c
+++ b/gtk/gtkmultiselection.c
@@ -378,7 +378,7 @@ gtk_multi_selection_new (GListModel *model)
 {
   GtkMultiSelection *self;
 
-  g_return_val_if_fail (G_IS_LIST_MODEL (model), NULL);
+  g_return_val_if_fail (model == NULL || G_IS_LIST_MODEL (model), NULL);
 
   self = g_object_new (GTK_TYPE_MULTI_SELECTION,
                        "model", model,
diff --git a/gtk/gtknoselection.c b/gtk/gtknoselection.c
index 36d4de008d..bc7363bbb8 100644
--- a/gtk/gtknoselection.c
+++ b/gtk/gtknoselection.c
@@ -224,7 +224,7 @@ gtk_no_selection_new (GListModel *model)
 {
   GtkNoSelection *self;
 
-  g_return_val_if_fail (G_IS_LIST_MODEL (model), NULL);
+  g_return_val_if_fail (model == NULL || G_IS_LIST_MODEL (model), NULL);
 
   self = g_object_new (GTK_TYPE_NO_SELECTION,
                        "model", model,
diff --git a/gtk/gtksingleselection.c b/gtk/gtksingleselection.c
index ad1cba6486..fcdd911503 100644
--- a/gtk/gtksingleselection.c
+++ b/gtk/gtksingleselection.c
@@ -460,7 +460,7 @@ gtk_single_selection_new (GListModel *model)
 {
   GtkSingleSelection *self;
 
-  g_return_val_if_fail (G_IS_LIST_MODEL (model), NULL);
+  g_return_val_if_fail (model == NULL || G_IS_LIST_MODEL (model), NULL);
 
   self = g_object_new (GTK_TYPE_SINGLE_SELECTION,
                        "model", model,
diff --git a/testsuite/gtk/multiselection.c b/testsuite/gtk/multiselection.c
index bbfaa2330f..c1457488e3 100644
--- a/testsuite/gtk/multiselection.c
+++ b/testsuite/gtk/multiselection.c
@@ -304,6 +304,17 @@ test_create (void)
   g_object_unref (selection);
 }
 
+static void
+test_create_empty (void)
+{
+  GtkMultiSelection *selection;
+
+  selection = gtk_multi_selection_new (NULL);
+  g_assert_cmpint (g_list_model_get_n_items (G_LIST_MODEL (selection)), ==, 0);
+
+  g_object_unref (selection);
+}
+
 static void
 test_changes (void)
 {
@@ -682,6 +693,7 @@ main (int argc, char *argv[])
   selection_quark = g_quark_from_static_string ("Mana mana, badibidibi");
 
   g_test_add_func ("/multiselection/create", test_create);
+  g_test_add_func ("/multiselection/create-empty", test_create_empty);
 #if GLIB_CHECK_VERSION (2, 58, 0) /* g_list_store_splice() is broken before 2.58 */
   g_test_add_func ("/multiselection/changes", test_changes);
 #endif
diff --git a/testsuite/gtk/singleselection.c b/testsuite/gtk/singleselection.c
index b94b38091f..85e1f4163b 100644
--- a/testsuite/gtk/singleselection.c
+++ b/testsuite/gtk/singleselection.c
@@ -304,6 +304,17 @@ test_create (void)
   g_object_unref (selection);
 }
 
+static void
+test_create_empty (void)
+{
+  GtkSingleSelection *selection;
+
+  selection = gtk_single_selection_new (NULL);
+  g_assert_cmpint (g_list_model_get_n_items (G_LIST_MODEL (selection)), ==, 0);
+
+  g_object_unref (selection);
+}
+
 static void
 test_changes (void)
 {
@@ -706,6 +717,7 @@ main (int argc, char *argv[])
   selection_quark = g_quark_from_static_string ("Mana mana, badibidibi");
 
   g_test_add_func ("/singleselection/create", test_create);
+  g_test_add_func ("/singleselection/create-empty", test_create_empty);
   g_test_add_func ("/singleselection/autoselect", test_autoselect);
   g_test_add_func ("/singleselection/autoselect-toggle", test_autoselect_toggle);
   g_test_add_func ("/singleselection/selection", test_selection);