[21.5] [BUG] save/restore window configuration

Test case: the following code snippet works fine on xemacs-21.4, xemacs-21.5-5 and GNU Emacs 21.2, all on Windows 2000 box. BUT in recent xemacs-21.5 from CVS it the second (error ...) clause fires an error -- the newly created window dies during (set-window-configuration ...) Nickolay. (let ((nw (split-window))) ; (save-window-excursion ; (select-window nw)) (let ((wc (current-window-configuration))) (unwind-protect (prog1 (select-window nw) (unless (window-live-p nw) (error 'error '(1)))) (set-window-configuration wc))) (unless (window-live-p nw) (error 'error '(2))) ) ------------------------------------------------------------------------------- OS version: Microsoft Windows 2000 [Version 5.00.2195] OS: Windows_NT XEmacs 21.5-b5 \"beets\" configured for `i586-pc-win32'. Building XEmacs in \"c:\\software\\SRC\\xemacs-beta\\nt\". Using compiler \"cl -nologo -W3 -O2 -G5 -ML\". Installing XEmacs in \"c:\\Program Files\\XEmacs\\XEmacs-21.5-b5\". Package path is \"~\\.xemacs;;c:\\Program Files\\XEmacs\\site-packages;c:\\Program Files\\XEmacs\\mule-packages;c:\\Program Files\\XEmacs\\xemacs-packages\". Compiling in support for Microsoft Windows native GUI. Compiling in international (MULE) support. Compiling in support for XPM images. Compiling in support for GIF images. Compiling in support for PNG images. Compiling in support for JPEG images. Compiling in support for GZIP compression/decompression. Compiling in support for toolbars. Compiling in support for dialogs. Compiling in support for widgets. Compiling in support for native sounds. Compiling in fast dired implementation.