(shell-mode): Don't assume /dev/null is its own truename.

diff --git a/lisp/shell.el b/lisp/shell.el
index 9d732bd3fd93d17e41ac3c1482caaeeaa910c903..1d4dfcef3c18553eca6553a454b05ab0b0a97ae9 100644 (file)
--- a/lisp/shell.el
+++ b/lisp/shell.el
@@ -357,7 +357,8 @@ buffer."
                    ((string-equal shell "ksh") "~/.sh_history")
                    (t "~/.history"))))
     (if (or (equal comint-input-ring-file-name "")
-           (equal (file-truename comint-input-ring-file-name) "/dev/null"))
+           (equal (file-truename comint-input-ring-file-name)
+                  (file-truename "/dev/null")))
        (setq comint-input-ring-file-name nil))
     (setq shell-dirstack-query
          (cond ((string-equal shell "sh") "pwd")