(help-make-xrefs): Avoid infloop in keymap substitutions

and change regexp for command names.
(help-xref-go-back, function-called-at-point, symbol-file)
(where-is): Doc fixes.
(help-xref-go-back): Remove interactive spec.
(describe-function-1): Fix message for alias.  Buttomize alias
name.

lisp/help.el

@@ -511,11 +511,9 @@ C-p Display information about the GNU project.
 C-w Display information on absence of warranty for GNU Emacs."
   help-map)
 
-;; Return a function whose name is around point.
-;; If that gives no function, return a function which is called by the
-;; list containing point.
-;; If that doesn't give a function, return nil.
 (defun function-called-at-point ()
+  "Return a function around point or else called by the list containing point.
+If that doesn't give a function, return nil."
   (let ((stab (syntax-table)))
     (set-syntax-table emacs-lisp-mode-syntax-table)
     (unwind-protect
@@ -552,7 +550,7 @@ That file records the part of `load-history' for preloaded files,
 which is cleared out before dumping to make Emacs smaller.")
 
 (defun symbol-file (function)
-  "Return the input source from which SYM was loaded.
+  "Return the input source from which FUNCTION was loaded.
 The value is normally a string that was passed to `load':
 either an absolute file name, or a library name
 \(with no directory name and no `.el' or `.elc' at the end).
@@ -635,6 +633,11 @@ It can also be nil, if the definition is not associated with any file."
       (setq need-close t)
       (princ "("))
     (princ string)
+    (with-current-buffer "*Help*"
+      (save-excursion
+	(save-match-data
+	  (if (re-search-backward "alias for `\\([^`']+\\)'" nil t)
+	      (help-xref-button 1 #'describe-function def)))))
     (or file-name
 	(setq file-name (symbol-file function)))
     (if file-name
@@ -683,8 +686,9 @@ It can also be nil, if the definition is not associated with any file."
 		 (help-setup-xref (list #'describe-function function) (interactive-p)))
 	(princ "not documented")))))
 
-;; We return 0 if we can't find a variable to return.
 (defun variable-at-point ()
+  "Return the bound variable symbol found around point.
+Return 0 if there is no such symbol."
   (condition-case ()
       (let ((stab (syntax-table)))
 	(unwind-protect
@@ -814,7 +818,7 @@ to display (default, the current buffer)."
 		     (interactive-p))))
 
 (defun where-is (definition &optional insert)
-  "Print message listing key sequences that invoke specified command.
+  "Print message listing key sequences that invoke the command DEFINITION.
 Argument is a command definition, usually a symbol with a function definition.
 If INSERT (the prefix arg) is non-nil, insert the message in the buffer."
   (interactive
@@ -848,7 +852,11 @@ Optional second arg NOSUFFIX non-nil means don't add suffixes `.elc' or `.el'
 to the specified name LIBRARY.
 
 If the optional third arg PATH is specified, that list of directories
-is used instead of `load-path'."
+is used instead of `load-path'.
+
+When called from a program, the file name is normaly returned as a
+string.  When run interactively, the argument INTERACTIVE-CALL is t,
+and the file name is displayed in the echo area."
   (interactive (list (read-string "Locate library: ")
 		     nil nil
 		     t))
@@ -1000,7 +1008,9 @@ that."
               ;; An obvious case of a key substitution:
               (save-excursion              
                 (while (re-search-forward
-                        "\\<M-x\\s-+\\(\\sw\\(\\sw\\|\\s_\\)+\\)" nil t)
+			;; Assume command name is only word characters
+			;; and dashes to get things like `use M-x foo.'.
+                        "\\<M-x\\s-+\\(\\sw\\(\\sw\\|-\\)+\\)" nil t)
                   (let ((sym (intern-soft (match-string 1))))
                     (if (fboundp sym)
                         (help-xref-button 1 #'describe-function sym)))))
@@ -1016,17 +1026,19 @@ that."
                     (while
                         ;; Ignore single blank lines in table, but not
                         ;; double ones, which should terminate it.
-                        (and (looking-at "^\n?[^\n]")
+                        (and (looking-at "^\n?[^\n\t ]")
                              (progn
                                (if (and (> (move-to-column col) 0)
-                                        (looking-at "\\(\\sw\\|\\s_\\)+$"))
+                                        (looking-at "\\(\\sw\\|-\\)+$"))
                                    ;; 
                                    (let ((sym (intern-soft (match-string 0))))
                                      (if (fboundp sym)
                                          (help-xref-button 
                                           0 #'describe-function sym))))
                                t)
-                             (zerop (forward-line))
+                             (progn
+			       (end-of-line)
+			       (zerop (forward-line)))
                              (move-to-column 0)))))))
           (set-syntax-table stab))
         ;; Make a back-reference in this buffer if appropriate.
@@ -1102,8 +1114,7 @@ help buffer."
       (help-follow pos))))
 
 (defun help-xref-go-back (buffer)
-  "Go back to the previous help buffer text using info on `help-xref-stack'."
-  (interactive)
+  "From BUFFER, go back to previous help buffer text using `help-xref-stack'."
   (let (item position method args)
     (with-current-buffer buffer
       (when help-xref-stack
@@ -1117,6 +1128,7 @@ help buffer."
     (goto-char position)))
 
 (defun help-go-back ()
+  "Invoke the [back] button (if any) in the Help mode buffer."
   (interactive)
   (help-follow (1- (point-max))))