[gnome-boxes] wizard: Disable customization for non-VMs for now

[Zeeshan Ali Khattak <zeeshanak src gnome org>]

commit 98bc9911c5a846f42894957880e440df82dede79
Author: Zeeshan Ali (Khattak) <zeeshanak gnome org>
Date:   Fri Oct 5 23:34:36 2012 +0300

    wizard: Disable customization for non-VMs for now
    
    Customization assumes a machine ready at 'review' page and that is
    currently only true when creating VMs. Since this feature is most useful
    for VMs (people wanting to change storage capacity and RAM) and its
    still very much possible to change machine properties after creation,
    lets go with this least intrusive solution for now.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=684233

 src/wizard.vala |    9 +++++----
 1 files changed, 5 insertions(+), 4 deletions(-)
---
diff --git a/src/wizard.vala b/src/wizard.vala
index c9ea47e..eb1090f 100644
--- a/src/wizard.vala
+++ b/src/wizard.vala
@@ -416,10 +416,11 @@ private class Boxes.Wizard: Boxes.UI {
             nokvm_label.visible = (machine.domain_config.get_virt_type () != GVirConfig.DomainVirtType.KVM);
         }
 
-        summary.append_customize_button (() => {
-            // Selecting an item in UIState.WIZARD implies changing state to UIState.PROPERTIES
-            App.app.select_item (machine);
-        });
+        if (machine != null) // Only allow customization of VMs for now
+            summary.append_customize_button (() => {
+                // Selecting an item in UIState.WIZARD implies changing state to UIState.PROPERTIES
+                App.app.select_item (machine);
+            });
 
         return true;
     }