bug#16405: info on non-existent node shows raw info buffer

bug#16405: info on non-existent node shows raw info buffer

[Glenn Morris]

Package: emacs
Version: 24.3

(info "(emacs)Node That Does Not Exist")

This dumps you in a raw, unformatted info buffer, which is not very
friendly. I think it should format the info buffer as normal, go to the
start, and only then return

user-error: No such node or anchor: Node That Does Not Exist

bug#16405: info on non-existent node shows raw info buffer

[Juri Linkov]

> (info "(emacs)Node That Does Not Exist")
>
> This dumps you in a raw, unformatted info buffer, which is not very
> friendly. I think it should format the info buffer as normal, go to the
> start, and only then return
>
> user-error: No such node or anchor: Node That Does Not Exist

AFAICS, this problem happens only when there is no *info* buffer
initially.  Otherwise, it recovers to the previously visited Info node.
So if there is no history then it could visit the Top node.

BTW, I see a similar problem with

  (info "(File That Does Not Exist)Node That Does Not Exist")

It displays an empty Info buffer.  I guess it would make sense to visit
the Dir node in this case. This patch should fix both problems:

=== modified file 'lisp/info.el'
--- lisp/info.el	2014-01-01 07:43:34 +0000
+++ lisp/info.el	2014-01-10 08:02:57 +0000
@@ -917,6 +917,8 @@ (defun Info-find-file (filename &optiona
 	  (setq filename found)
 	(if noerror
 	    (setq filename nil)
+	  (unless Info-history
+	    (Info-directory))
 	  (error "Info file %s does not exist" filename)))
       filename))))
 
@@ -1238,11 +1240,13 @@ (defun Info-find-node-2 (filename nodena
 		   (setq Info-point-loc nil))))))
     ;; If we did not finish finding the specified node,
     ;; go back to the previous one.
-    (or Info-current-node no-going-back (null Info-history)
-        (let ((hist (car Info-history)))
-          (setq Info-history (cdr Info-history))
-          (Info-find-node (nth 0 hist) (nth 1 hist) t)
-          (goto-char (nth 2 hist))))))
+    (unless (or Info-current-node no-going-back)
+      (if Info-history
+	  (let ((hist (car Info-history)))
+	    (setq Info-history (cdr Info-history))
+	    (Info-find-node (nth 0 hist) (nth 1 hist) t)
+	    (goto-char (nth 2 hist)))
+	(Info-find-node (or filename Info-current-file) "Top" t)))))
 
 ;; Cache the contents of the (virtual) dir file, once we have merged
 ;; it for the first time, so we can save time subsequently.

bug#16405: info on non-existent node shows raw info buffer

[Eli Zaretskii]

> From: Juri Linkov <juri@jurta.org>
> Date: Fri, 10 Jan 2014 10:04:11 +0200
> Cc: 16405@debbugs.gnu.org
> 
> BTW, I see a similar problem with
> 
>   (info "(File That Does Not Exist)Node That Does Not Exist")
> 
> It displays an empty Info buffer.  I guess it would make sense to visit
> the Dir node in this case.

Only if you are not in Info already, I hope.  Otherwise, visiting DIR
doesn't make sense: we should stay put in the node where we were.

bug#16405: info on non-existent node shows raw info buffer

[Juri Linkov]

>>   (info "(File That Does Not Exist)Node That Does Not Exist")
>>
>> It displays an empty Info buffer.  I guess it would make sense to visit
>> the Dir node in this case.
>
> Only if you are not in Info already, I hope.  Otherwise, visiting DIR
> doesn't make sense: we should stay put in the node where we were.

This is fixed now to visit DIR only if no previous node is already visited.

bug#16405: info on non-existent node shows raw info buffer

[Eli Zaretskii]

> From: Juri Linkov <juri@jurta.org>
> Cc: rgm@gnu.org,  16405-done@debbugs.gnu.org
> Date: Mon, 13 Jan 2014 10:05:03 +0200
> 
> >>   (info "(File That Does Not Exist)Node That Does Not Exist")
> >>
> >> It displays an empty Info buffer.  I guess it would make sense to visit
> >> the Dir node in this case.
> >
> > Only if you are not in Info already, I hope.  Otherwise, visiting DIR
> > doesn't make sense: we should stay put in the node where we were.
> 
> This is fixed now to visit DIR only if no previous node is already visited.

Thank you.