X-Git-Url: https://code.delx.au/gnu-emacs/blobdiff_plain/194959c7004fd196285029efca0ace1f5401a851..d365421f859f6c88e3dc4b610c87adaef3cb099c:/lisp/help.el

diff --git a/lisp/help.el b/lisp/help.el
index e45061536a..c3dfc518aa 100644
--- a/lisp/help.el
+++ b/lisp/help.el
@@ -621,7 +621,9 @@ It can also be nil, if the definition is not associated with any file."
 		     (vectorp def))
 		 "a keyboard macro")
 		((subrp def)
-		 (concat beg "built-in function"))
+		 (if (eq 'unevalled (cdr (subr-arity def)))
+		     (concat beg "special form")
+		   (concat beg "built-in function")))
 		((byte-code-function-p def)
 		 (concat beg "compiled Lisp function"))
 		((symbolp def)
@@ -716,19 +718,35 @@ It can also be nil, if the definition is not associated with any file."
       (if doc
 	  (progn (terpri)
 		 (princ doc)
-		 (with-current-buffer standard-output
-		   (beginning-of-line)
-		   ;; Builtins get the calling sequence at the end of
-		   ;; the doc string.  Move it to the same place as
-		   ;; for other functions.
-		   (when (looking-at (format "(%S[ )]" function))
-		     (let ((start (point-marker)))
-		       (goto-char (point-min))
-		       (forward-paragraph)
-		       (insert-buffer-substring (current-buffer) start)
-		       (insert ?\n)
-		       (delete-region (1- start) (point-max))
-		       (goto-char (point-max)))))
+		 (if (subrp (symbol-function function))
+		     (with-current-buffer standard-output
+		       (beginning-of-line)
+		       ;; Builtins get the calling sequence at the end of
+		       ;; the doc string.  Move it to the same place as
+		       ;; for other functions.
+
+		       ;; In cases where `function' has been fset to a
+		       ;; subr we can't search for function's name in
+		       ;; the doc string.  Kluge round that using the
+		       ;; printed representation.  The arg list then
+		       ;; shows the wrong function name, but that
+		       ;; might be a useful hint.
+		       (let* ((rep (prin1-to-string def))
+			      (name (progn
+				      (string-match " \\([^ ]+\\)>$" rep)
+				      (match-string 1 rep))))
+			 (if (looking-at (format "(%s[ )]" name))
+			     (let ((start (point-marker)))
+			       (goto-char (point-min))
+			       (forward-paragraph)
+			       (insert-buffer-substring (current-buffer) start)
+			       (insert ?\n)
+			       (delete-region (1- start) (point-max)))
+			   (goto-char (point-min))
+			   (forward-paragraph)
+			   (insert
+			    "[Missing arglist.  Please make a bug report.]\n")))
+		       (goto-char (point-max))))
 		 (help-setup-xref (list #'describe-function function)
 				  interactive-p))
 	(princ "not documented")))))
@@ -829,13 +847,16 @@ Returns the documentation as a string, also."
 	    (set-buffer standard-output)
 	    (if (> (count-lines (point-min) (point-max)) 10)
 		(progn
+		  ;; Note that setting the syntax table like below
+		  ;; makes forward-sexp move over a `'s' at the end
+		  ;; of a symbol.
 		  (set-syntax-table emacs-lisp-mode-syntax-table)
 		  (goto-char (point-min))
 		  (if valvoid
 		      (forward-line 1)
 		    (forward-sexp 1)
 		    (delete-region (point) (progn (end-of-line) (point)))
-		    (insert "'s value is shown below.\n\n")
+		    (insert " value is shown below.\n\n")
 		    (save-excursion
 		      (insert "\n\nValue:"))))))
 	  (princ "Documentation:")