Simplified.

[elisp/epg.git] / epg.el

diff --git a/epg.el b/epg.el
index 60af26d..ca9b4c6 100644 (file)
--- a/epg.el
+++ b/epg.el
@@ -522,7 +522,54 @@ This function is for internal use only."
       (setq alist (cdr alist)))
     (nreverse result)))
 
-(defalias 'epg-make-temp-file 'make-temp-file)
+(if (fboundp 'make-temp-file)
+    (defalias 'epg-make-temp-file 'make-temp-file)
+  ;; stolen from poe.el.
+  (defun epg-make-temp-file (prefix)
+    "Create a temporary file.
+The returned file name (created by appending some random characters at the end
+of PREFIX, and expanding against `temporary-file-directory' if necessary),
+is guaranteed to point to a newly created empty file.
+You can then use `write-region' to write new data into the file."
+    (let (tempdir tempfile)
+      (unwind-protect
+         (let (file)
+           ;; First, create a temporary directory.
+           (while (condition-case ()
+                      (progn
+                        (setq tempdir (make-temp-name
+                                       (concat
+                                        (file-name-directory prefix)
+                                        "DIR")))
+                        ;; return nil or signal an error.
+                        (make-directory tempdir))
+                    ;; let's try again.
+                    (file-already-exists t)))
+           (set-file-modes tempdir 448)
+           ;; Second, create a temporary file in the tempdir.
+           ;; There *is* a race condition between `make-temp-name'
+           ;; and `write-region', but we don't care it since we are
+           ;; in a private directory now.
+           (setq tempfile (make-temp-name (concat tempdir "/EMU")))
+           (write-region "" nil tempfile nil 'silent)
+           (set-file-modes tempfile 384)
+           ;; Finally, make a hard-link from the tempfile.
+           (while (condition-case ()
+                      (progn
+                        (setq file (make-temp-name prefix))
+                        ;; return nil or signal an error.
+                        (add-name-to-file tempfile file))
+                    ;; let's try again.
+                    (file-already-exists t)))
+           file)
+       ;; Cleanup the tempfile.
+       (and tempfile
+            (file-exists-p tempfile)
+            (delete-file tempfile))
+       ;; Cleanup the tempdir.
+       (and tempdir
+            (file-directory-p tempdir)
+            (delete-directory tempdir))))))
 
 ;;;###autoload
 (defun epg-decrypt-start (context input-file)