bug#16793: window-state-put needs a live window

[martin rudalics]

> But I still think that getting a window-state for a window and putting
> it again into the same window should always be allowed, unless Martin
> has a good reason why that symmetry is a bad idea.

I tend to agree with you.  But the obvious consequence is that the
WINDOW argument of `window-state-put' could then specify an internal
window that is not the root window of its frame.  In this case plain
`delete-other-windows' would be the wrong action.  I attach a patch.

martin

=== modified file 'lisp/window.el'
--- lisp/window.el      2014-02-10 01:34:22 +0000
+++ lisp/window.el      2014-02-18 18:59:17 +0000
@@ -5026,14 +5026,29 @@
   "Put window state STATE into WINDOW.
 STATE should be the state of a window returned by an earlier
 invocation of `window-state-get'.  Optional argument WINDOW must
-specify a live window and defaults to the selected one.
+specify a valid window and defaults to the selected one.  If
+WINDOW is not live, delete all child windows of WINDOW before
+putting STATE.

 Optional argument IGNORE non-nil means ignore minimum window
 sizes and fixed size restrictions.  IGNORE equal `safe' means
 windows can get as small as `window-safe-min-height' and
 `window-safe-min-width'."
   (setq window-state-put-stale-windows nil)
-  (setq window (window-normalize-window window t))
+  (setq window (window-normalize-window window))
+
+  (unless (window-live-p window)
+    (let ((root (frame-root-window)))
+      (if (eq window root)
+         (setq window (frame-first-window root))
+       (setq root window)
+       (setq window (catch 'live
+                      (walk-window-subtree
+                       (lambda (window)
+                         (when (window-live-p window)))
+                       root))))
+      (delete-other-windows-internal window root)))
+
   (let* ((frame (window-frame window))
         (head (car state))
         ;; We check here (1) whether the total sizes of root window of