[gtk/printing-portal-fix-master] Remember to call print_cb even if print operation is cancelled.

[Matthias Clasen <matthiasc src gnome org>]

commit cc8bb5fc545d854b0ae6ea54270974e8846e645e
Author: Casey Jao <casey jao gmail com>
Date:   Wed Jul 8 23:31:49 2020 -0400

    Remember to call print_cb even if print operation is cancelled.
    
    Closes #2917.

 gtk/gtkprintoperation-portal.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)
---
diff --git a/gtk/gtkprintoperation-portal.c b/gtk/gtkprintoperation-portal.c
index eb155a78b6..15bf35c7bc 100644
--- a/gtk/gtkprintoperation-portal.c
+++ b/gtk/gtkprintoperation-portal.c
@@ -427,7 +427,15 @@ prepare_print_response (GDBusConnection *connection,
       g_free (filename);
     }
   else
-    portal->result = GTK_PRINT_OPERATION_RESULT_CANCEL;
+    {
+      portal->result = GTK_PRINT_OPERATION_RESULT_CANCEL;
+
+      if (portal->print_cb)
+        portal->print_cb (portal->op, portal->parent, portal->do_print, portal->result);
+
+      if (portal->destroy)
+        portal->destroy (portal);
+    }
 
   if (options)
     g_variant_unref (options);