martin f krafft writes:

I can confirm that the behaviour is much better: the window size is
restored, as is the position, but it gives preference to the
Xinerama head. You'd think it restores at the same *relative*
position on the current head, but it actually just restores
somewhere $,1rt(B I cannot figure out the behaviour.

The position is entirely up to your window manager.

However, I still wonder why we have to do this at all.

Well, try it without... :)

Restoring the overall window size and the positions of the sashes of
the panedwindows is the simplest and most reliable method I have found
for making the window come back the way the user last set it.

I understand
that Cygwin has issues and needs this code, but couldn't it then be
made to run only on Cygwin, such that on "proper" Unix systems, the
config file is *not* updated every time I move the window before
closing the application?

What's the issue with updating the config file?

As I said earlier, this is really the job
of a window manager, *not* a configuration option. If your window
manager cannot restore the window to a size you control, then it's
broken. Let's not hack applications to work around that, please.

I disagree.  It's not a window manager's job to tell an application
how big its window should be.

Paul.