bug#17776: 24.3; bug? regression: xterm-mouse-mode does not work any more with rxvt-unicode

bug#17776: 24.3; bug? regression: xterm-mouse-mode does not work any more with rxvt-unicode

[Gregor Zattler]

xterm-mouse-mode used to work under rxvt-unicode but does not any more.
I'm not sure who ist to blame (emacs or rxvt-unicode).

How to reproduce:

start emacs like so:

urxvt -e emacs-snapshot -Q -nw --eval '(progn (xterm-mouse-mode 1)(switch-to-buffer "*Messages*")(toggle-debug-on-error))'

then klick in the one window.  You'll see a backtrace etc.

I see:
- in *Messages*

Entering debugger...
[ is undefined
M is undefined
# is undefined
@ is undefined


- backtrace:
Debugger entered--Lisp error: (wrong-type-argument stringp nil)
  intern(nil)
  xterm-mouse--read-event-sequence-1000()
  xterm-mouse-event(nil)
  xterm-mouse-translate-1()
  xterm-mouse-translate(nil)


This happens with
rxvt-unicode (urxvt) v9.20 - released: 2014-04-26
options:
perl,xft,styles,combining,blink,iso14755,unicode3,encodings=eu+vn+jp+jp-ext+kr+zh+zh-ext,fade,transparent,tint,pixbuf,XIM,frills,selectionscrolling,wheel,slipwheel,smart-resize,cursorBlink,pointerBlank,scrollbars=plain+rxvt+NeXT+xterm


I git-bisected this:

da26b804bfee2a137e999bb03c736bf85dd3bf5a is the first bad commit
commit da26b804bfee2a137e999bb03c736bf85dd3bf5a
Author: Stefan Monnier <monnier@iro.umontreal.ca>
Date:   Wed May 7 21:46:15 2014 -0400

    * lisp/xt-mouse.el: Drop spurious/oddly shaped events.
    (xterm-mouse--read-event-sequence-1000): Return nil if something looks fishy.
    (xterm-mouse-event): Propagate it.
    (xterm-mouse-translate-1): Handle it.

:040000 040000 bfe3c645c9b390c2bca2aa5b114ec10594142782 42a69b7988a9f3bc90a86a26401b5036ac41f876 M      lisp


HTH, thanks for your attention, Gregor



In GNU Emacs 24.3.1 (i486-pc-linux-gnu, X toolkit, Xaw3d scroll bars)
 of 2014-05-16 on babin, modified by Debian
System Description:	Debian GNU/Linux testing (jessie)

Configured using:
 `configure '--build' 'i486-linux-gnu' '--build' 'i486-linux-gnu'
 '--prefix=/usr' '--sharedstatedir=/var/lib' '--libexecdir=/usr/lib'
 '--localstatedir=/var/lib' '--infodir=/usr/share/info'
 '--mandir=/usr/share/man' '--with-pop=yes'
 '--enable-locallisppath=/etc/emacs24:/etc/emacs:/usr/local/share/emacs/24.3/site-lisp:/usr/local/share/emacs/site-lisp:/usr/share/emacs/24.3/site-lisp:/usr/share/emacs/site-lisp'
 '--with-crt-dir=/usr/lib/i386-linux-gnu' '--with-x=yes'
 '--with-x-toolkit=lucid' '--with-toolkit-scroll-bars' '--without-gconf'
 '--without-gsettings' 'build_alias=i486-linux-gnu' 'CFLAGS=-g -O2
 -fstack-protector --param=ssp-buffer-size=4 -Wformat
 -Werror=format-security -Wall' 'LDFLAGS=-Wl,-z,relro'
 'CPPFLAGS=-D_FORTIFY_SOURCE=2''

Important settings:
  value of $LC_COLLATE: de_DE.utf8
  value of $LC_CTYPE: de_DE.utf8
  value of $LC_MESSAGES: POSIX
  value of $LC_MONETARY: de_DE.utf8
  value of $LC_NUMERIC: de_DE.utf8
  value of $LC_TIME: de_DE.utf8
  value of $LANG: de_DE.utf8
  locale-coding-system: utf-8-unix
  default enable-multibyte-characters: t

Major mode: Lisp Interaction

Minor modes in effect:
  tooltip-mode: t
  mouse-wheel-mode: t
  tool-bar-mode: t
  menu-bar-mode: t
  file-name-shadow-mode: t
  global-font-lock-mode: t
  font-lock-mode: t
  auto-composition-mode: t
  auto-encryption-mode: t
  auto-compression-mode: t
  line-number-mode: t
  transient-mark-mode: t

Recent input:
ESC x r e p o r t - e m a TAB RET

Recent messages:
("emacs24")
Loading term/xterm...done
For information about GNU Emacs and the GNU system, type C-h C-a.

Load-path shadows:
None found.

Features:
(shadow sort gnus-util mail-extr emacsbug message format-spec rfc822 mml
easymenu mml-sec mm-decode mm-bodies mm-encode mail-parse rfc2231
mailabbrev gmm-utils mailheader sendmail rfc2047 rfc2045 ietf-drums
mm-util mail-prsvr mail-utils time-date tooltip ediff-hook vc-hooks
lisp-float-type mwheel x-win x-dnd tool-bar dnd fontset image regexp-opt
fringe tabulated-list newcomment lisp-mode register page menu-bar
rfn-eshadow timer select scroll-bar mouse jit-lock font-lock syntax
facemenu font-core frame cham georgian utf-8-lang misc-lang vietnamese
tibetan thai tai-viet lao korean japanese hebrew greek romanian slovak
czech european ethiopic indian cyrillic chinese case-table epa-hook
jka-cmpr-hook help simple abbrev minibuffer loaddefs button faces
cus-face macroexp files text-properties overlay sha1 md5 base64 format
env code-pages mule custom widget hashtable-print-readable backquote
make-network-process dbusbind dynamic-setting font-render-setting
x-toolkit x multi-tty emacs)

bug#17776: 24.3; bug? regression: xterm-mouse-mode does not work any more with rxvt-unicode

[Stefan Monnier]

severity 17776 important
found 17776 24.3.91
thanks

> xterm-mouse-mode used to work under rxvt-unicode but does not any more.
> I'm not sure who ist to blame (emacs or rxvt-unicode).

IIUC you're saying it worked in 24.3 but it fails in 24.3.91, right
(the email subject seems to say that it fails in 24.3, but the commit
to which you bisected indicates the problem is new).



        Stefan

bug#17776: 24.3; bug? regression: xterm-mouse-mode does not work any more with rxvt-unicode

[Gregor Zattler]

Hi Stefan,
* Stefan Monnier <monnier@iro.umontreal.ca> [14. Jun. 2014]:
> severity 17776 important
> found 17776 24.3.91
> thanks
> 
>> xterm-mouse-mode used to work under rxvt-unicode but does not any more.
>> I'm not sure who ist to blame (emacs or rxvt-unicode).
> 
> IIUC you're saying it worked in 24.3 but it fails in 24.3.91, right
> (the email subject seems to say that it fails in 24.3, but the commit
> to which you bisected indicates the problem is new).

Yes, right, the version number in the subject is wrong.  I
actually tried to follow your advise from bug#17724 to use
24.3.9x in order to find bugs before the 24.4 release...

Thanks for looking into this, Gregor

bug#17776: 24.3; bug? regression: xterm-mouse-mode does not work any more with rxvt-unicode

[Stefan Monnier]

> Yes, right, the version number in the subject is wrong.  I
> actually tried to follow your advise from bug#17724 to use
> 24.3.9x in order to find bugs before the 24.4 release...

Great, thanks, so yes I can reproduce the problem here.
It looks like rxvt-unicode uses yet some other escape sequences for
mouse clicks which are not documented (but somehow worked) in the code.


        Stefan

bug#17776: 24.3; bug? regression: xterm-mouse-mode does not work any more with rxvt-unicode

[Stefan Monnier]

> Great, thanks, so yes I can reproduce the problem here.
> It looks like rxvt-unicode uses yet some other escape sequences for
> mouse clicks which are not documented (but somehow worked) in the code.

No, it was just a dump error on my part in the last change.
I installed the patch below which fixes it.  Sorry, and thanks for
reporting it.


        Stefan


--- lisp/xt-mouse.el	2014-05-08 01:46:15 +0000
+++ lisp/xt-mouse.el	2014-06-18 21:58:58 +0000
@@ -76,7 +76,7 @@
 	     (is-down (string-match "down" (symbol-name (car down)))))
 
 	;; Retrieve the expected preface for the up-event.
-	(unless is-down
+	(when is-down
 	  (unless (cond ((null extension)
 			 (and (eq (read-event) ?\e)
 			      (eq (read-event) ?\[)