Fix race condition in epg.el compat code.

* lisp/epg.el (epg--make-temp-file): Avoid permission race condition
when running on old Emacs versions.

Fixes: debbugs:10403
This commit is contained in:
Paul Eggert 2012-01-14 15:09:15 +08:00 committed by Chong Yidong
parent 3cdb7f5a38
commit 9e5788aaef
2 changed files with 9 additions and 3 deletions

View file

@ -1,3 +1,8 @@
2012-01-14 Paul Eggert <eggert@cs.ucla.edu>
* epg.el (epg--make-temp-file): Avoid permission race condition
when running on old Emacs versions (bug#10403).
2012-01-14 Glenn Morris <rgm@gnu.org>
* dired.el (dired-get-filename): Fix 'verbatim case of previous change.

View file

@ -1951,7 +1951,8 @@ 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)
(let ((orig-modes (default-file-modes))
tempdir tempfile)
(setq prefix (expand-file-name prefix
(if (featurep 'xemacs)
(temp-directory)
@ -1959,6 +1960,7 @@ You can then use `write-region' to write new data into the file."
(unwind-protect
(let (file)
;; First, create a temporary directory.
(set-default-file-modes #o700)
(while (condition-case ()
(progn
(setq tempdir (make-temp-name
@ -1969,14 +1971,12 @@ You can then use `write-region' to write new data into the file."
(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
@ -1986,6 +1986,7 @@ You can then use `write-region' to write new data into the file."
;; let's try again.
(file-already-exists t)))
file)
(set-default-file-modes orig-modes)
;; Cleanup the tempfile.
(and tempfile
(file-exists-p tempfile)