gtk: port many nullability annotation fixes from Vala bindings

https://bugzilla.gnome.org/show_bug.cgi?id=730745

4 files changed, 16 insertions, 14 deletions

diff --git a/gtk/deprecated/gtkactiongroup.c b/gtk/deprecated/gtkactiongroup.c
index 737dbf1951..a08d18c74c 100644
--- a/gtk/deprecated/gtkactiongroup.c
+++ b/gtk/deprecated/gtkactiongroup.c
@@ -1154,7 +1154,7 @@ shared_data_unref (gpointer data)
  * @entries: (array length=n_entries): an array of action descriptions
  * @n_entries: the number of entries
  * @user_data: data to pass to the action callbacks
- * @destroy: destroy notification callback for @user_data
+ * @destroy: (nullable): destroy notification callback for @user_data
  *
  * This variant of gtk_action_group_add_actions() adds a #GDestroyNotify
  * callback for @user_data. 
@@ -1265,7 +1265,7 @@ gtk_action_group_add_toggle_actions (GtkActionGroup             *action_group,
  * @entries: (array length=n_entries): an array of toggle action descriptions
  * @n_entries: the number of entries
  * @user_data: data to pass to the action callbacks
- * @destroy: destroy notification callback for @user_data
+ * @destroy: (nullable): destroy notification callback for @user_data
  *
  * This variant of gtk_action_group_add_toggle_actions() adds a 
  * #GDestroyNotify callback for @user_data. 
diff --git a/gtk/deprecated/gtkhscale.c b/gtk/deprecated/gtkhscale.c
index 557287488e..f5db3c9e55 100644
--- a/gtk/deprecated/gtkhscale.c
+++ b/gtk/deprecated/gtkhscale.c
@@ -68,7 +68,8 @@ gtk_hscale_init (GtkHScale *hscale)
 
 /**
  * gtk_hscale_new:
- * @adjustment: the #GtkAdjustment which sets the range of the scale.
+ * @adjustment: (nullable): the #GtkAdjustment which sets the range of
+ * the scale.
  *
  * Creates a new #GtkHScale.
  *
diff --git a/gtk/deprecated/gtkrc.c b/gtk/deprecated/gtkrc.c
index 17f47be7cf..1e8efbbbcb 100644
--- a/gtk/deprecated/gtkrc.c
+++ b/gtk/deprecated/gtkrc.c
@@ -1409,11 +1409,12 @@ gtk_rc_get_style (GtkWidget *widget)
  *                             G_OBJECT_TYPE (widget));
  * ]|
  *
- * Returns: (transfer none): A style created by matching with the
- *     supplied paths, or %NULL if nothing matching was specified and the
- *     default style should be used. The returned value is owned by GTK+
- *     as part of an internal cache, so you must call g_object_ref() on
- *     the returned value if you want to keep a reference to it.
+ * Returns: (nullable) (transfer none): A style created by matching
+ *     with the supplied paths, or %NULL if nothing matching was
+ *     specified and the default style should be used. The returned
+ *     value is owned by GTK+ as part of an internal cache, so you
+ *     must call g_object_ref() on the returned value if you want to
+ *     keep a reference to it.
  *
  * Deprecated:3.0: Use #GtkStyleContext instead
  **/
diff --git a/gtk/deprecated/gtkstyle.c b/gtk/deprecated/gtkstyle.c
index 5c1ef7a7c9..55ad766d2d 100644
--- a/gtk/deprecated/gtkstyle.c
+++ b/gtk/deprecated/gtkstyle.c
@@ -4498,12 +4498,12 @@ gtk_widget_modify_base (GtkWidget      *widget,
 /**
  * gtk_widget_modify_cursor:
  * @widget: a #GtkWidget
- * @primary: the color to use for primary cursor (does not need to be
- *     allocated), or %NULL to undo the effect of previous calls to
- *     of gtk_widget_modify_cursor().
- * @secondary: the color to use for secondary cursor (does not need to be
- *     allocated), or %NULL to undo the effect of previous calls to
- *     of gtk_widget_modify_cursor().
+ * @primary: (nullable): the color to use for primary cursor (does not
+ *     need to be allocated), or %NULL to undo the effect of previous
+ *     calls to of gtk_widget_modify_cursor().
+ * @secondary: (nullable): the color to use for secondary cursor (does
+ *     not need to be allocated), or %NULL to undo the effect of
+ *     previous calls to of gtk_widget_modify_cursor().
  *
  * Sets the cursor color to use in a widget, overriding the #GtkWidget
  * cursor-color and secondary-cursor-color