(describe-key): No error when UNTRANSLATED is nil.

1 files changed, 3 insertions, 1 deletions

diff --git a/lisp/help.el b/lisp/help.el
index e65982623c1..76fc43d63ef 100644
--- a/lisp/help.el
+++ b/lisp/help.el
@@ -611,6 +611,7 @@ pass a string or a vector.
 If non-nil UNTRANSLATED is a vector of the untranslated events.
 It can also be a number in which case the untranslated events from
 the last key hit are used."
+  ;; UP-EVENT is the up-event that was discarded by reading KEY, or nil.
   (interactive "kDescribe key: \np\nU")
   (if (numberp untranslated)
       (setq untranslated (this-single-command-raw-keys)))
@@ -634,7 +635,8 @@ the last key hit are used."
           ;; Don't bother user with strings from (e.g.) the select-paste menu.
           (if (stringp (aref key (1- (length key))))
               (aset key (1- (length key)) "(any string)"))
-          (if (stringp (aref untranslated (1- (length untranslated))))
+          (if (and untranslated
+                   (stringp (aref untranslated (1- (length untranslated)))))
               (aset untranslated (1- (length untranslated))
                     "(any string)"))
           (with-output-to-temp-buffer (help-buffer)