bug#37948: [PATCH] Add doc for goto-history-element.

[Hong Xu <hong@topbug.net>]

* lisp/simple.el (goto-history-element): Clarify NABS.

* doc/lispref/minibuf.texi (Minibuffer Commands): Add goto-history-element.
---
 doc/lispref/minibuf.texi | 6 ++++++
 lisp/simple.el           | 4 +++-
 2 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/doc/lispref/minibuf.texi b/doc/lispref/minibuf.texi
index dd51181db009..d5a160140532 100644
--- a/doc/lispref/minibuf.texi
+++ b/doc/lispref/minibuf.texi
@@ -2334,6 +2334,12 @@ Minibuffer Commands
 contents of the minibuffer before the point.
 @end deffn
 
+@deffn Command goto-history-element nabs
+Puts element of the minibuffer history in the minibuffer.  The
+argument @var{nabs} specifies the absolute history position in
+descending order, where 0 means the current element and a positive
+number N means the Nth previous element.
+@end deffn
 
 @node Minibuffer Windows
 @section Minibuffer Windows
diff --git a/lisp/simple.el b/lisp/simple.el
index 5502cd49aa42..fcd271527075 100644
--- a/lisp/simple.el
+++ b/lisp/simple.el
@@ -2128,7 +2128,9 @@ minibuffer-default-add-completions
 
 (defun goto-history-element (nabs)
   "Puts element of the minibuffer history in the minibuffer.
-The argument NABS specifies the absolute history position."
+The argument NABS specifies the absolute history position in
+descending order, where 0 means the current element and a
+positive number N means the Nth previous element."
   (interactive "p")
   (when (and (not minibuffer-default-add-done)
 	     (functionp minibuffer-default-add-function)
-- 
2.20.1