(display-time-file-nonempty-p): Check existence here.

(display-time-server-down-time): New variable.
(display-time-filter): If accessing mail-spool-time takes too long,
don't try again for twenty minutes.

1 files changed, 27 insertions, 7 deletions

diff --git a/lisp/time.el b/lisp/time.el
index 3f89438a802..bcd0ae445fc 100644
--- a/lisp/time.el
+++ b/lisp/time.el
@@ -49,6 +49,10 @@ Nil means 1 <= hh <= 12, and an AM/PM suffix is used.")
 (defvar display-time-hook nil
   "* List of functions to be called when the time is updated on the mode line.")
 
+(defvar display-time-server-down-time nil
+   "Time when mail file's file system was recorded to be down.
+If that file system seems to be up, the value is nil.")
+
 ;;;###autoload
 (defun display-time ()
   "Display current time, load level, and mail flag in mode line of each buffer.
@@ -97,7 +101,7 @@ After each update, `display-time-hook' is run with `run-hooks'."
                                      (or (getenv "LOGNAME")
                                          (getenv "USER")
                                          (user-login-name)))))
-        hour am-pm-flag)
+        hour am-pm-flag mail-flag)
     (setq hour (read (substring time 11 13)))
     (if (not display-time-24hr-format)
         (progn
@@ -107,15 +111,30 @@ After each update, `display-time-hook' is run with `run-hooks'."
             (if (= hour 0)
                 (setq hour 12))))
       (setq am-pm-flag ""))
+    (setq mail-flag
+          (if (and (or (null display-time-server-down-time)
+                       ;; If have been down for 20 min, try again.
+                       (> (- (nth 1 (current-time))
+                             display-time-server-down-time)
+                          1200))
+                   (let ((start-time (current-time)))
+                     (prog1
+                         (display-time-file-nonempty-p mail-spool-file)
+                       (if (> (- (nth 1 (current-time)) (nth 1 start-time))
+                              20)
+                           ;; Record that mail file is not accessible.
+                           (setq display-time-server-down-time 
+                                 (nth 1 (current-time)))
+                         ;; Record that mail file is accessible.
+                         (setq display-time-server-down-time nil))
+                       )))
+              " Mail"
+            ""))
     (setq display-time-string
           (concat (format "%d" hour) (substring time 13 16)
                   am-pm-flag
                   load
-                  (if (and (file-exists-p mail-spool-file)
-                           ;; file not empty?
-                           (display-time-file-nonempty-p mail-spool-file))
-                      " Mail"
-                    "")))
+                  mail-flag))
     ;; Append the date if desired.
     (if display-time-day-and-date
         (setq display-time-string
@@ -128,6 +147,7 @@ After each update, `display-time-hook' is run with `run-hooks'."
   (sit-for 0))
 
 (defun display-time-file-nonempty-p (file)
-  (< 0 (nth 7 (file-attributes (file-chase-links file)))))
+  (and (file-exists-p file)
+       (< 0 (nth 7 (file-attributes (file-chase-links file))))))
 
 ;;; time.el ends here