safely.lisp: Hacking for CLisp support.

CLisp's RENAME-FILE doesn't like it if the target exists.  Insert a
shim function, and get it to use low-level hacking on CLisp.

diff --git a/safely.lisp b/safely.lisp
index 2477f9a721b7350fb997e31d97937a30b43d39af..8cd0f9a635dd6e137414f46448bba475a23e473a 100644 (file)
--- a/safely.lisp
+++ b/safely.lisp
@@ -104,6 +104,11 @@ (defun safely-open-output-stream (safe file &rest open-args)
          (safely-trail safe))
     stream))
 
+(declaim (inline rename))
+(defun rename (old new)
+  #-clisp (rename-file old new)
+  #+clisp (posix:copy-file old new :method :rename))
+
 (defun delete-file-without-moaning (file)
   "Delete the FILE, ignoring errors."
   (handler-case (delete-file file)
@@ -112,7 +117,7 @@ (defun delete-file-without-moaning (file)
 (defun rename-file-without-moaning (old new)
   "Rename OLD to NEW, ignoring errors, and without doing any stupid name
    mangling."
-  (handler-case (rename-file old new)
+  (handler-case (rename old new)
     (file-error () nil)))
 
 (defun safely-unwind (trail)
@@ -158,6 +163,14 @@ (defun safe-copy (file tag)
                                (and from to
                                     (unix-link from to)))))
 
+  #+clisp
+  (generate-fresh-file-name file tag
+                           (lambda (name)
+                             (>= (unix:link (namestring file) 
+                                            (namestring name))
+                                 0)))
+
+
   #-(or cmu sbcl)
   ;; Otherwise just copy the file contents and hope for the best.
   (with-open-file (input file :element-type :default)
@@ -207,7 +220,7 @@ (defun safely-commit (safe)
                                  (push `(:rmtmp ,old) cleanup)
                                  (push `(:revert ,old ,file) revert))
                                (push `(:rmtmp ,file) revert))
-                           (rename-file new file)))
+                           (rename new file)))
                  (:delete (destructuring-bind (tag file) job
                             (declare (ignore tag))
                             (let ((old (safe-copy file "delete")))