_NET_WM_STATE_HIDDEN change breaks iconification

[Daniel Drake <dsd laptop org>]

Hi,

The following commit has broken iconification for me:

commit 1c970036648bffd5d58499bb7c8e2439b84d4397
Author: Mikael Magnusson <mikachu gmail com>
Date:   Tue Feb 21 17:14:16 2012 +0100

    Iconification using _NET_WM_STATE_HIDDEN hint if supported by WM

    If the Window Manager supports the _NET_WM_STATE_HIDDEN, we use it to use
    the _NET_WM_STATE protocol when de-iconifying windows (iconification is
    unchanged, via XIconifyWindow). Additionally, we no longer interpret all
    UnmapNotify events for our window as the result of iconification.

Testing under metacity-2.34.8 (GNOME fallback on F18), the following
simple test case that creates a window that is iconified from the
start cannot be deiconified on first attempt:
http://dev.laptop.org/~dsd/20120920/iconify.py

Launch the app, it will create an iconified window which is shown as
[iconified] in gnome-panel's window switcher. The output so far is:

window_state_event changed=<flags GDK_WINDOW_STATE_ICONIFIED of type
GdkWindowState> new=<flags GDK_WINDOW_STATE_WITHDRAWN |
GDK_WINDOW_STATE_ICONIFIED of type GdkWindowState>
window_state_event changed=<flags GDK_WINDOW_STATE_WITHDRAWN |
GDK_WINDOW_STATE_FOCUSED of type GdkWindowState> new=<flags
GDK_WINDOW_STATE_ICONIFIED | GDK_WINDOW_STATE_FOCUSED of type
GdkWindowState>


Click on the entry in the window switcher in order to deiconify and
activate the window. The window doesn't appear as you would hope, and
metacity's iconification animation confusingly kicks in. As this
happens this output appears:

window_state_event changed=<flags GDK_WINDOW_STATE_ICONIFIED of type
GdkWindowState> new=<flags GDK_WINDOW_STATE_FOCUSED of type
GdkWindowState>
gdk_synthesize_window_state w=35651587 unset=0 set=2
window_state_event changed=<flags GDK_WINDOW_STATE_ICONIFIED of type
GdkWindowState> new=<flags GDK_WINDOW_STATE_ICONIFIED |
GDK_WINDOW_STATE_FOCUSED of type GdkWindowState>

Not even GTK+ can deiconify this window via gtk_window_deiconify().
There's a commented-out line in the test app that you can uncomment to
show this. The output and behaviour is the same as above.

This issue is breaking the loading of the Journal under the Sugar
learning environment.

Any ideas?

Thanks,
Daniel