(eshell/which): Handle the case where no description is found.

1 files changed, 6 insertions, 3 deletions

diff --git a/lisp/eshell/esh-cmd.el b/lisp/eshell/esh-cmd.el
index 82619d60791..17ae50d1f50 100644
--- a/lisp/eshell/esh-cmd.el
+++ b/lisp/eshell/esh-cmd.el
@@ -1252,9 +1252,12 @@ be finished later after the completion of an asynchronous subprocess."
                               (prog1
                                   (describe-function sym)
                                 (message nil))))))
-                (setq desc (substring desc 0
-                                      (1- (or (string-match "\n" desc)
-                                              (length desc)))))
+                (setq desc (if desc (substring desc 0
+                                               (1- (or (string-match "\n" desc)
+                                                       (length desc))))
+                             ;; This should not happen.
+                             (format "%s is defined, \
+but no documentation was found" name)))
                 (if (buffer-live-p (get-buffer "*Help*"))
                     (kill-buffer "*Help*"))
                 (setq program (or desc name))))))