[Emacs-diffs] emacs/lisp files.el

[Richard M. Stallman]

CVSROOT:        /cvsroot/emacs
Module name:    emacs
Changes by:     Richard M. Stallman <rms>       08/12/22 19:48:08

Modified files:
        lisp           : files.el 

Log message:
        (buffer-swapped-with): New variable.
        (basic-save-buffer-0): Most of basic-save-buffer moved here.
        (basic-save-buffer): Unswap the buffer temporarily if nec.

CVSWeb URLs:
http://cvs.savannah.gnu.org/viewcvs/emacs/lisp/files.el?cvsroot=emacs&r1=1.1024&r2=1.1025

Patches:
Index: files.el
===================================================================
RCS file: /cvsroot/emacs/emacs/lisp/files.el,v
retrieving revision 1.1024
retrieving revision 1.1025
diff -u -b -r1.1024 -r1.1025
--- files.el    9 Dec 2008 23:43:11 -0000       1.1024
+++ files.el    22 Dec 2008 19:48:08 -0000      1.1025
@@ -4065,6 +4065,13 @@
 (make-variable-buffer-local 'save-buffer-coding-system)
 (put 'save-buffer-coding-system 'permanent-local t)
 
+(defvar buffer-swapped-with nil
+  "Buffer that this buffer's contents are temporarily swapped with.
+You should only set this variable in file-visiting buffers,
+because it only affects how to save the buffer in its file.")
+
+(make-variable-buffer-local 'buffer-swapped-with)
+
 (defun basic-save-buffer ()
   "Save the current buffer in its visited file, if it has been modified.
 The hooks `write-contents-functions' and `write-file-functions' get a chance
@@ -4073,6 +4080,17 @@
 Before and after saving the buffer, this function runs
 `before-save-hook' and `after-save-hook', respectively."
   (interactive)
+  (if (not buffer-swapped-with)
+      (basic-save-buffer-0)
+    ;; If this buffer's real contents are "swapped" with some other buffer,
+    ;; temporarily unswap in order to save the real contents.
+    (unwind-protect
+       (progn
+         (buffer-swap-text buffer-swapped-with)
+         (basic-save-buffer-0))
+      (buffer-swap-text buffer-swapped-with))))
+
+(defun basic-save-buffer-0 ()
   (save-current-buffer
     ;; In an indirect buffer, save its base buffer instead.
     (if (buffer-base-buffer)