(byte-compile-file): Remove TARGET-FILE before writing it, so that

hard-links don't see new version.

1 files changed, 9 insertions, 2 deletions

diff --git a/lisp/emacs-lisp/bytecomp.el b/lisp/emacs-lisp/bytecomp.el
index ae74752d9e6..7e6fbeea10c 100644
--- a/lisp/emacs-lisp/bytecomp.el
+++ b/lisp/emacs-lisp/bytecomp.el
@@ -1,6 +1,6 @@
 ;;; bytecomp.el --- compilation of Lisp code into byte code
 
-;; Copyright (C) 1985, 1986, 1987, 1992, 1994, 1998, 2000
+;; Copyright (C) 1985, 1986, 1987, 1992, 1994, 1998, 2000, 2001
 ;;   Free Software Foundation, Inc.
 
 ;; Author: Jamie Zawinski <jwz@lucid.com>
@@ -10,7 +10,7 @@
 
 ;;; This version incorporates changes up to version 2.10 of the
 ;;; Zawinski-Furuseth compiler.
-(defconst byte-compile-version "$Revision: 2.83 $")
+(defconst byte-compile-version "$Revision: 2.84 $")
 
 ;; This file is part of GNU Emacs.
 
@@ -1406,6 +1406,13 @@ The value is t if there were no errors, nil if errors."
               (let ((coding-system-for-write 'no-conversion))
                 (if (or (eq system-type 'ms-dos) (eq system-type 'windows-nt))
                     (setq buffer-file-type t))
+                (when (file-exists-p target-file)
+                  ;; Remove the target before writing it, so that any
+                  ;; hard-links continue to point to the old file (this makes
+                  ;; it possible for installed files to share disk space with
+                  ;; the build tree, without causing problems when emacs-lisp
+                  ;; files in the build tree are recompiled).
+                  (delete-file target-file))
                 (write-region 1 (point-max) target-file))
             ;; This is just to give a better error message than
             ;; write-region