bug#19443: 25.0.50; `info-display-manual' could limit the choice to currently visited manuals if given a prefix arg for convenience

[Filipp Gunbin <fgunbin@fastmail.fm>]

Here's the patch on the subject.  I'll apply it if no one objects.

Filipp

diff --git a/etc/NEWS b/etc/NEWS
index 14933aa..9e0c9c7 100644
--- a/etc/NEWS
+++ b/etc/NEWS
@@ -338,6 +338,11 @@ The remainder were:
 ---
 ** `Info-fontify-maximum-menu-size' can be t for no limit.
 
++++
+** `info-display-manual' can now be given a prefix argument which (any
+non-nil value) directs the command to limit the choice of manual to
+currently visited manuals.
+
 ---
 ** ntlm.el has support for NTLM2.
 
diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index a2bee14..3119d80 100644
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -1,3 +1,8 @@
+2014-12-26  Filipp Gunbin  <fgunbin@fastmail.fm>
+
+	* info.el (info-display-manual): Limit the choice of manuals to
+	currently visited if prefix argument is non-nil.
+
 2014-12-25  Helmut Eller  <eller.helmut@gmail.com>
             Dmitry Gutov  <dgutov@yandex.ru>
 
diff --git a/lisp/info.el b/lisp/info.el
index 7c4d7f3..c5e3b21 100644
--- a/lisp/info.el
+++ b/lisp/info.el
@@ -5277,13 +5277,15 @@ type returned by `Info-bookmark-make-record', which see."
 (defun info-display-manual (manual)
   "Display an Info buffer displaying MANUAL.
 If there is an existing Info buffer for MANUAL, display it.
-Otherwise, visit the manual in a new Info buffer."
+Otherwise, visit the manual in a new Info buffer.  In interactive
+use, a prefix argument directs this command to limit the choice
+to currently visited manuals."
   (interactive
    (list
     (progn
       (info-initialize)
       (completing-read "Manual name: "
-		       (info--manual-names)
+		       (info--manual-names current-prefix-arg)
 		       nil t))))
   (let ((blist (buffer-list))
 	(manual-re (concat "\\(/\\|\\`\\)" manual "\\(\\.\\|\\'\\)"))
@@ -5302,7 +5304,7 @@ Otherwise, visit the manual in a new Info buffer."
       (info (Info-find-file manual)
 	    (generate-new-buffer-name "*info*")))))
 
-(defun info--manual-names ()
+(defun info--manual-names (visited-only)
   (let (names)
     (dolist (buffer (buffer-list))
       (with-current-buffer buffer
@@ -5313,11 +5315,12 @@ Otherwise, visit the manual in a new Info buffer."
 		    (file-name-nondirectory Info-current-file))
 		   names))))
     (delete-dups (append (nreverse names)
-			 (all-completions
-			  ""
-			  (apply-partially 'Info-read-node-name-2
-					   Info-directory-list
-					   (mapcar 'car Info-suffix-list)))))))
+			 (when (not visited-only)
+			   (all-completions
+			    ""
+			    (apply-partially 'Info-read-node-name-2
+					     Info-directory-list
+					     (mapcar 'car Info-suffix-list))))))))
 
 (provide 'info)