OK, I can confirm that your branch sucessfully builds a working gtk-window-decorator, 
and that the resulting binary can even be dropped into an install of current compiz 0.9.13.0,
I will be uploading a compiz Debian package with both this and your older gtk-extents patch
to my Archive site tonight.

Sorry about any mixups concerning the code: the metacity changes apparently looked more
intrusive than they actually were. I never saw your new branch, I even looked for it figuring 
there might be one but  didn't find it.

On 10/25/2016 at 4:31 AM, "Alberts Muktupāvels" <email address hidden> wrote:
>
>Branch with needed changes/fix is available! It was available in 
>same
>day when Metacity 3.22.0 was released.
>
>"Not sure a port to 3.22 would even still give the ability to read 
>Metacity themes anyway, given the first commit listed above."
>How about doing some research before speaking about something you 
>have no idea? Metacity can still use Metacity themes.
>
>"libmetacity: switch from .ssd to .csd"
>This commit has nothing to do with Metacity themes. Metacity now 
>supports both - GTK+ themes and also Metacity themes. Your 
>mentioned commit affects only GTK+ theme.
>
>"I haven't spoken with the GNOME people about this, I don't think 
>they would
>consider the failure of any non-GNOME package to build against a 
>GNOME
>package other than GTK to be a bug, or the report to be a feature 
>request."
>I have always updated gtk-window-decorator for all changes I have 
>made to Metacity. Otherwise gdw probably would still use GTK+ 2...
>
>"It would be possible to fork and rename libmetacity 3.20."
>Ah, forking, world saver, right?
>
>"To port compiz to 3.22 would not bring back metacity
>theme support I'm pretty sure, instead giving support for using 
>the GTK CSD
>theme as Metacity itself has done for a couple releases now."
>You are so wrong...
>
>"GNOME simply does not use this code anymore and does not even 
>ship metacity themes."
>I removed Metacity themes, because:
>- metacity by default use GTK+ theme
>- all metacity themes was unmaintained
>
>** Changed in: compiz
>     Assignee: (unassigned) => Alberts Muktupāvels 
>(albertsmuktupavels)
>
>-- 
>You received this bug notification because you are subscribed to 
>the bug
>report.
>https://bugs.launchpad.net/bugs/1629749
>
>Title:
>  window-decorator cannot build with libmetacity 3.22
>
>Status in Compiz:
>  New
>
>Bug description:
>  This is with compiz source 
>  compiz_0.9.13.0+16.10.20160818.2.orig.tar.gz
>  build on Debian Unstable (not Ubuntu) and GTK 3.22 and Metacity 
>3.22. Will become an issue for Ubuntu post-yakkety unless Ubuntu 
>pins Metacity at version 3.20.
>
>  Metacity/libmetacity 3.22 introduced radical changes that totally
>  break compiz's gtk-window-decorator,which can neither build nor 
>run
>  against it. I played with it, a whole bunch of things compiz 
>needed to
>  link against were removed. This was the first error resulting 
>from an
>  attempt to build against Metacity 3.22:
>
>  error: unknown type name ‘MetaButtonLayout’
>       MetaButtonLayout            button_layout;
>
>  
>  The possible killer for Metacity theme support:
>
>  
>https://github.com/GNOME/metacity/commit/d7f2445ec7e70274c7501586a5
>37c699f6628335
>  libmetacity: switch from .ssd to .csd 
>
>  and some of the changes probably behind breaking the build:
>
>  
>https://github.com/GNOME/metacity/commit/2ee0ffbee0b52cb8fc3112906b
>ea1eaa737559f7
>  libmetacity: don't expose MetaButton struct 
>
>  
>  
>https://github.com/GNOME/metacity/commit/eee199e3b7ce87cbd08b4b6e4c
>9c55c804c6ff5f
>  libmetacity: rename MetaButtonFunction to MetaButtonType 
>
>  Not sure a port to 3.22 would even still give the ability to read
>  Metacity themes anyway, given the first commit listed above.
>
>  Meanwhile, building gtk-window-decorator without metacity 
>support at
>  all was broken accidently in changes to support metacity 3.20 by 
>using
>  metacity version selectors but not checking to see if Metacity 
>support
>  is being used at all.
>
>  I build compiz for use in Debian Unstable (and offer my builds 
>for
>  public use) so I saw this a couple days ago. All I could so was 
>switch
>  decorators to Emerald (which compiz-reloaded has ported to GTK3) 
>and
>  use the Emerald pixmap engine to write an Emerald theme matched 
>to my
>  metacity theme.  Ubuntu MATE may have to do the same post-Yakkety
>  unless Ubuntu either pins Metacity, gets a 3.22 port to work and 
>finds
>  it handles metacity themes, or modified gtk-window-decorator to 
>read
>  metacity themes directly without using libmetacity.
>
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