* lisp/help-fns.el (describe-function-1): Check file-name is a string before

calling help-fns--autoloaded-p.

Fixes: debbugs:17564

2 files changed, 6 insertions, 1 deletions

diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index 5981c50af77..f0fecd95e9f 100644
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -1,3 +1,8 @@
+2014-06-25  Stefan Monnier  <monnier@iro.umontreal.ca>
+
+        * help-fns.el (describe-function-1): Check file-name is a string before
+        calling help-fns--autoloaded-p (bug#17564).
+
 2014-06-24  Juri Linkov  <juri@jurta.org>
 
         * desktop.el (desktop-auto-save-enable)
diff --git a/lisp/help-fns.el b/lisp/help-fns.el
index 5b0739ed9ae..46b73701835 100644
--- a/lisp/help-fns.el
+++ b/lisp/help-fns.el
@@ -460,7 +460,7 @@ FILE is the file where FUNCTION was probably defined."
          (beg (if (and (or (byte-code-function-p def)
                            (keymapp def)
                            (memq (car-safe def) '(macro lambda closure)))
-                       file-name
+                       (stringp file-name)
                        (help-fns--autoloaded-p function file-name))
                   (if (commandp def)
                       "an interactive autoloaded "