bug#23887: 25.1.50; Detect aliases to built-in functions

[Tino Calancha <tino.calancha@gmail.com>]

emacs -Q

F1 f search-forward-regexp RET
;; First line don't mention that the func is an alias
;; Compare, for instance, with
F1 f chmod RET


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From 48dcc336e96bbd22250eaee7e3a46c91b7ede1a1 Mon Sep 17 00:00:00 2001
From: Tino Calancha <tino.calancha@gmail.com>
Date: Sun, 3 Jul 2016 18:01:24 +0900
Subject: [PATCH] Detect aliases to built-in functions

* lisp/help-fns.el (describe-function-1): Check for aliases
defined with (defalias alias (symbol-function built-in)) (Bug#23887).
---
  lisp/help-fns.el | 16 ++++++++++------
  1 file changed, 10 insertions(+), 6 deletions(-)

diff --git a/lisp/help-fns.el b/lisp/help-fns.el
index 9464c0b..e4e2333 100644
--- a/lisp/help-fns.el
+++ b/lisp/help-fns.el
@@ -572,13 +572,17 @@ describe-function-1
  	 (aliased (or (symbolp def)
  		      ;; Advised & aliased function.
  		      (and advised (symbolp real-function)
-			   (not (eq 'autoload (car-safe def))))))
+			   (not (eq 'autoload (car-safe def))))
+                      (and (subrp def)
+                           (not (string= (subr-name def)
+                                         (symbol-name function))))))
  	 (real-def (cond
-		    (aliased (let ((f real-function))
-			       (while (and (fboundp f)
-					   (symbolp (symbol-function f)))
-				 (setq f (symbol-function f)))
-			       f))
+                    ((and aliased (not (subrp def)))
+                     (let ((f real-function))
+                       (while (and (fboundp f)
+                                   (symbolp (symbol-function f)))
+                         (setq f (symbol-function f)))
+                       f))
  		    ((subrp def) (intern (subr-name def)))
  		    (t def)))
  	 (sig-key (if (subrp def)
-- 
2.8.1



In GNU Emacs 25.1.50.1 (x86_64-pc-linux-gnu, GTK+ Version 3.20.6)
of 2016-07-03 built
Repository revision: 08974112ae68aefba658a8516c8faa3374edc924