* files.el (get-free-disk-space): Change fallback default

directory to /.  Expand DIR argument before switching to fallback.
Suggested by Kevin Ryde (Bug#2631, Bug#3911).

2 files changed, 15 insertions, 7 deletions

diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index 6c339b6d4b1..6961e82c6d2 100644
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -1,3 +1,9 @@
+2009-08-16  Chong Yidong  <cyd@stupidchicken.com>
+
+        * files.el (get-free-disk-space): Change fallback default
+        directory to /.  Expand DIR argument before switching to fallback.
+        Suggested by Kevin Ryde (Bug#2631, Bug#3911).
+
 2009-08-15  Chong Yidong  <cyd@stupidchicken.com>
 
         * files.el (load-library): Doc fix.
diff --git a/lisp/files.el b/lisp/files.el
index 966036a15e4..6f8ff69caef 100644
--- a/lisp/files.el
+++ b/lisp/files.el
@@ -5386,7 +5386,7 @@ fail.  It returns also nil when DIR is a remote directory.
 
 This function calls `file-system-info' if it is available, or invokes the
 program specified by `directory-free-space-program' if that is non-nil."
-  (when (not (file-remote-p dir))
+  (unless (file-remote-p dir)
     ;; Try to find the number of free blocks.  Non-Posix systems don't
     ;; always have df, but might have an equivalent system call.
     (if (fboundp 'file-system-info)
@@ -5396,12 +5396,14 @@ program specified by `directory-free-space-program' if that is non-nil."
       (save-match-data
         (with-temp-buffer
           (when (and directory-free-space-program
-                     (let ((default-directory
-                             (if (and (not (file-remote-p default-directory))
-                                      (file-directory-p default-directory)
-                                      (file-readable-p default-directory))
-                                 default-directory
-                               (expand-file-name "~/"))))
+                     ;; Avoid failure if the default directory does
+                     ;; not exist (Bug#2631, Bug#3911).
+                     (let ((default-directory default-directory))
+                       (setq dir (expand-file-name dir))
+                       (unless (and (not (file-remote-p default-directory))
+                                    (file-directory-p default-directory)
+                                    (file-readable-p default-directory))
+                         (setq default-directory "/"))
                        (eq (call-process directory-free-space-program
                                          nil t nil
                                          directory-free-space-args