(file-truename): Don't raise args-out-of-range error

when filename has no separator on windows-nt.  (Bug#982)

2 files changed, 11 insertions, 2 deletions

diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index 4bbc8597270..c3c4835ad9e 100644
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -1,3 +1,8 @@
+2008-09-15  Martin Rudalics  <rudalics@gmx.at>
+
+        * files.el (file-truename): Don't raise args-out-of-range error
+        when filename has no separator on windows-nt.  (Bug#982)
+
 2008-09-14  Stefan Monnier  <monnier@iro.umontreal.ca>
 
         * diff-mode.el (diff-find-file-name): Rename `batch' to `noprompt' and
diff --git a/lisp/files.el b/lisp/files.el
index 76e50247d6f..2773c9f14b0 100644
--- a/lisp/files.el
+++ b/lisp/files.el
@@ -856,10 +856,14 @@ containing it, until no links are left at any level.
                   missing rest)
               (if longname
                   (setq filename longname)
-                ;; include the preceding directory separator in the missing
+                ;; Include the preceding directory separator in the missing
                 ;; part so subsequent recursion on the rest works.
                 (setq missing (concat "/" (file-name-nondirectory filename)))
-                (setq rest (substring filename 0 (* -1 (length missing))))
+                (let ((length (length missing)))
+                  (setq rest
+                        (if (> length (length filename))
+                            ""
+                          (substring filename 0 (- length)))))
                 (setq filename (concat (file-truename rest) missing))))))
         (setq done t)))