bug#4271: 23.1; pop-to-buffer -vs- multiple terminals

bug#4271: 23.1; pop-to-buffer -vs- multiple terminals

[Tom Tromey]

Please write in English if possible, because the Emacs maintainers
usually do not have translators to read other languages for them.

Your bug report will be posted to the bug-gnu-emacs@gnu.org mailing list,
and to the gnu.emacs.bug news group.

Please describe exactly what actions triggered the bug
and the precise symptoms of the bug:


I have a long-running emacs on one machine.  It has a couple of frames
on the local X display.

I logged into that machine remotely and ran 'emacsclient -t' on a tty.

When I ran vc-diff on this terminal, I was surprised that I was not
switched to the *vc-diff* buffer.  It turns out that *vc-diff* was in a
window on one of the X frames -- but not visible to me now, using the
tty.

I ran (pop-to-buffer "*vc-diff*") and this did not show the buffer.  I
think that this should ignore frames on other terminals when determining
whether a buffer is visible.


If Emacs crashed, and you have the Emacs process in the gdb debugger,
please include the output from the following gdb commands:
    `bt full' and `xbacktrace'.
If you would like to further debug the crash, please read the file
/usr/share/emacs/23.1/etc/DEBUG for instructions.


In GNU Emacs 23.1.1 (i386-redhat-linux-gnu, GTK+ Version 2.16.5)
 of 2009-08-24 on x86-2.fedora.phx.redhat.com
Windowing system distributor `The X.Org Foundation', version 11.0.10601901
configured using `configure  '--build=i386-redhat-linux-gnu' '--host=i386-redhat-linux-gnu' '--target=i586-redhat-linux-gnu' '--program-prefix=' '--prefix=/usr' '--exec-prefix=/usr' '--bindir=/usr/bin' '--sbindir=/usr/sbin' '--sysconfdir=/etc' '--datadir=/usr/share' '--includedir=/usr/include' '--libdir=/usr/lib' '--libexecdir=/usr/libexec' '--localstatedir=/var' '--sharedstatedir=/var/lib' '--mandir=/usr/share/man' '--infodir=/usr/share/info' '--with-dbus' '--with-gif' '--with-jpeg' '--with-png' '--with-rsvg' '--with-tiff' '--with-xft' '--with-xpm' '--with-x-toolkit=gtk' 'build_alias=i386-redhat-linux-gnu' 'host_alias=i386-redhat-linux-gnu' 'target_alias=i586-redhat-linux-gnu' 'CFLAGS=-DMAIL_USE_LOCKF -O2 -g -pipe -Wall -Wp,-D_FORTIFY_SOURCE=2 -fexceptions -fstack-protector --param=ssp-bu
 ffer-size=4 -m32 -march=i586 -mtune=generic -fasynchronous-unwind-tables''

Important settings:
  value of $LC_ALL: nil
  value of $LC_COLLATE: nil
  value of $LC_CTYPE: nil
  value of $LC_MESSAGES: nil
  value of $LC_MONETARY: nil
  value of $LC_NUMERIC: nil
  value of $LC_TIME: nil
  value of $LANG: en_US.UTF-8
  value of $XMODIFIERS: nil
  locale-coding-system: utf-8-unix
  default-enable-multibyte-characters: t

Major mode: C/l

Minor modes in effect:
  shell-dirtrack-mode: t
  diff-auto-refine-mode: t
  auto-fill-function: tjt-c++-do-auto-fill
  erc-list-mode: t
  erc-menu-mode: t
  erc-autojoin-mode: t
  erc-ring-mode: t
  erc-pcomplete-mode: t
  erc-track-mode: t
  erc-track-minor-mode: t
  erc-match-mode: t
  erc-button-mode: t
  erc-fill-mode: t
  erc-stamp-mode: t
  erc-netsplit-mode: t
  erc-spelling-mode: t
  erc-truncate-mode: t
  flyspell-mode: t
  erc-status-mode: t
  erc-services-mode: t
  erc-networks-mode: t
  erc-irccontrols-mode: t
  erc-noncommands-mode: t
  erc-move-to-prompt-mode: t
  erc-readonly-mode: t
  tooltip-mode: t
  mouse-wheel-mode: t
  file-name-shadow-mode: t
  global-font-lock-mode: t
  font-lock-mode: t
  global-auto-composition-mode: t
  auto-composition-mode: t
  auto-encryption-mode: t
  auto-compression-mode: t
  line-number-mode: t
  transient-mark-mode: t
  abbrev-mode: t

Recent input:
v C-l C-x v d ESC DEL RET C-x 1 = <switch-frame> C-f 
C-f = <switch-frame> = <switch-frame> = <switch-frame> 
= <switch-frame> = <switch-frame> = <switch-frame> 
C-x b * v c d DEL - d i f f TAB RET C-v C-v C-v ESC 
v C-l ESC v ESC v ESC v C-l C-v ESC < C-x C-f b u f 
f e r ESC b s r c / C-e . c RET ESC < C-s p t h r e 
a d . C-a C-l C-k C-k C-k C-x C-s C-x s C-x b RET C-x 
v = C-v ESC [ 2 1 ~ C-c b C-p C-b C-v C-l C-u C-n C-u 
C-n C-u C-n C-l C-u C-n C-u C-n C-l ESC [ 2 0 ~ C-x 
1 ESC [ 2 1 ~ C-c b C-x C-f b u f f e r . c RET C-x 
b * G TAB RET 1 g C-v C-v C-s p a t h c DEL c h C-a 
C-u C-n C-n C-n = ESC > SPC Q y SPC ESC > Q y SPC 5 
0 RET ESC > q s ESC v ESC v ESC v C-l C-u C-p C-p ESC 
g ESC g ESC g ESC g ESC g n n n ESC g ESC g ESC g s 
z C-c b ESC [ 2 1 ~ ESC [ 2 1 ~ ESC [ 2 1 ~ ESC [ 2 
1 ~ C-c b ESC v C-x v = <switch-frame> ESC : ( p o 
p - t o - b u f f e r SPC " * v c - d i f f * " ) RET 
<switch-frame> ESC x r e p o r t - e m TAB b u TAB 
RET

Recent messages:
Saving /home/tromey/.newsrc.eld...done
call-interactively: Beginning of buffer
Opening nntp server on redhat...done
Opening nntp server on news.gmane.org...done
(No changes need to be saved)
Saving /home/tromey/.newsrc.eld...
Saving file /home/tromey/.newsrc.eld...
Wrote /home/tromey/.newsrc.eld
Saving /home/tromey/.newsrc.eld...done
Finding changes in /home/tromey/gnu/Emacs/git-emacs/emacs/src/buffer.c...done
#<buffer *vc-diff*>
Tom

bug#4271: 23.1; pop-to-buffer -vs- multiple terminals

[Stefan Monnier]

> I ran (pop-to-buffer "*vc-diff*") and this did not show the buffer.  I
> think that this should ignore frames on other terminals when determining
> whether a buffer is visible.

Does the patch below help?


        Stefan


=== modified file 'lisp/window.el'
--- lisp/window.el	2009-07-24 02:42:43 +0000
+++ lisp/window.el	2009-08-27 05:16:51 +0000
@@ -1307,7 +1307,7 @@
 	(old-frame (selected-frame))
 	new-window new-frame)
     (set-buffer buffer)
-    (setq new-window (display-buffer buffer other-window))
+    (setq new-window (display-buffer buffer other-window 0))
     (unless (eq new-window old-window)
       ;; `display-buffer' has chosen another window, select it.
       (select-window new-window norecord)

bug#4271: 23.1; pop-to-buffer -vs- multiple terminals

[martin rudalics]

 > When I ran vc-diff on this terminal, I was surprised that I was not
 > switched to the *vc-diff* buffer.  It turns out that *vc-diff* was in a
 > window on one of the X frames -- but not visible to me now, using the
 > tty.
 >
 > I ran (pop-to-buffer "*vc-diff*") and this did not show the buffer.  I
 > think that this should ignore frames on other terminals when determining
 > whether a buffer is visible.

Could you please edebug `display-buffer' and find out how the `let' part
below gets executed in your case

      ((let ((frames (or frame
			(and (or use-pop-up-frames
				 display-buffer-reuse-frames
				 (not (last-nonminibuffer-frame)))
			     0)
			(last-nonminibuffer-frame))))
	(setq window-to-use
	      (catch 'found
		;; Search frames for a window displaying BUFFER.  Return
		;; the selected window only if we are allowed to do so.
		(dolist (window (get-buffer-window-list buffer 'nomini frames))
		  (when (or can-use-selected-window
			    (not (eq (selected-window) window)))
		    (throw 'found window))))))

Thanks, martin.

bug#4271: 23.1; pop-to-buffer -vs- multiple terminals

[Chong Yidong]

> I ran (pop-to-buffer "*vc-diff*") and this did not show the buffer.  I
> think that this should ignore frames on other terminals when
> determining whether a buffer is visible.

The pop-to-buffer code has been completely rewritten since this bug was
filed, and AFAICT the new code will not reuse a window on a different
terminal unless you specifically force it to.  Closing.