ob-screen tempfile fixes

* lisp/org/ob-screen.el (org-babel-screen-session-write-temp-file)
(org-babel-screen-test): Use unpredictable names for temporary files.

Fixes: debbugs:17416

lisp/org/ChangeLog

+2014-05-12  Eric Schulte  <eric.schulte@gmx.com>
+
+	* ob-screen.el (org-babel-screen-session-write-temp-file)
+	(org-babel-screen-test):
+	Use unpredictable names for temporary files.  (Bug#17416)
+
 2014-04-22  Aaron Ecay  <aaronecay@gmail.com>
 	* org-src.el (org-edit-src-exit): Place an undo boundary before

lisp/org/ob-screen.el

@@ -106,7 +106,7 @@ In case you want to use a different screen than one selected by your $PATH")
 
 (defun org-babel-screen-session-write-temp-file (session body)
   "Save BODY in a temp file that is named after SESSION."
-  (let ((tmpfile (concat "/tmp/screen.org-babel-session-" session)))
+  (let ((tmpfile (org-babel-temp-file "screen-")))
     (with-temp-file tmpfile
       (insert body)
 
@@ -121,7 +121,7 @@ The terminal should shortly flicker."
   (interactive)
   (let* ((session "org-babel-testing")
          (random-string (format "%s" (random 99999)))
-         (tmpfile "/tmp/org-babel-screen.test")
+         (tmpfile (org-babel-temp-file "ob-screen-test-"))
          (body (concat "echo '" random-string "' > " tmpfile "\nexit\n"))
          process tmp-string)
     (org-babel-execute:screen body org-babel-default-header-args:screen)