1 files changed, 13 insertions, 19 deletions

diff --git a/lisp/eshell/esh-cmd.el b/lisp/eshell/esh-cmd.el
index 86e7b83c281..24342208771 100644
--- a/lisp/eshell/esh-cmd.el
+++ b/lisp/eshell/esh-cmd.el
@@ -1148,6 +1148,8 @@ be finished later after the completion of an asynchronous subprocess."
 
 ;; command invocation
 
+(declare-function help-fns-function-description-header "help-fns")
+
 (defun eshell/which (command &rest names)
   "Identify the COMMAND, and where it is located."
   (dolist (name (cons command names))
@@ -1164,25 +1166,17 @@ be finished later after the completion of an asynchronous subprocess."
                 (concat name " is an alias, defined as \""
                         (cadr alias) "\"")))
       (unless program
-        (setq program (eshell-search-path name))
-        (let* ((esym (eshell-find-alias-function name))
-               (sym (or esym (intern-soft name))))
-          (if (and (or esym (and sym (fboundp sym)))
-                   (or eshell-prefer-lisp-functions (not direct)))
-              (let ((desc (let ((inhibit-redisplay t))
-                            (save-window-excursion
-                              (prog1
-                                  (describe-function sym)
-                                (message nil))))))
-                (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))))))
+        (setq program
+              (let* ((esym (eshell-find-alias-function name))
+                     (sym (or esym (intern-soft name))))
+                (if (and (or esym (and sym (fboundp sym)))
+                         (or eshell-prefer-lisp-functions (not direct)))
+                    (or (with-output-to-string
+                          (require 'help-fns)
+                          (princ (format "%s is " sym))
+                          (help-fns-function-description-header sym))
+                        name)
+                  (eshell-search-path name)))))
       (if (not program)
           (eshell-error (format "which: no %s in (%s)\n"
                                 name (getenv "PATH")))