[devhelp] App: destroy all GtkWindows for the quit GAction

[Sébastien Wilmet <swilmet src gnome org>]

commit 23e09a0134af9772de86a9adc2d1815d14d0118d
Author: Sébastien Wilmet <swilmet gnome org>
Date:   Thu Dec 28 21:00:44 2017 +0100

    App: destroy all GtkWindows for the quit GAction

 src/dh-app.c |   12 ++++++++++--
 1 files changed, 10 insertions(+), 2 deletions(-)
---
diff --git a/src/dh-app.c b/src/dh-app.c
index 56ac945..228bfc9 100644
--- a/src/dh-app.c
+++ b/src/dh-app.c
@@ -96,9 +96,17 @@ quit_cb (GSimpleAction *action,
          GVariant      *parameter,
          gpointer       user_data)
 {
-        DhApp *app = DH_APP (user_data);
+        GtkApplication *app = GTK_APPLICATION (user_data);
+        GList *windows;
 
-        g_application_quit (G_APPLICATION (app));
+        /* Do not call g_application_quit(). If g_application_quit() is called
+         * the GtkWindows are not finalized. A GtkWindow subclass may want to
+         * save some GSettings when the window is closed, so it's better to
+         * properly close all the windows. And it's also more friendly to memory
+         * debugging tools.
+         */
+        while ((windows = gtk_application_get_windows (app)) != NULL)
+                gtk_widget_destroy (GTK_WIDGET (windows->data));
 }
 
 static void