Strange behaviour of track-mouse and make-local-variable

Strange behaviour of track-mouse and make-local-variable

[Torsten Hilbrich]

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In GNU Emacs 21.2.1 (i386-debian-linux-gnu, X toolkit, Xaw3d scroll bars)
 of 2002-03-22 on raven, modified by Debian
configured using `configure  i386-debian-linux-gnu --prefix=/usr --sharedstatedir=/var/lib --libexecdir=/usr/lib --localstatedir=/var/lib --infodir=/usr/share/info --mandir=/usr/share/man --with-pop=yes --with-x=yes --with-x-toolkit=athena --without-gif'
Important settings:
  value of $LC_ALL: nil
  value of $LC_COLLATE: nil
  value of $LC_CTYPE: de_DE
  value of $LC_MESSAGES: POSIX
  value of $LC_MONETARY: nil
  value of $LC_NUMERIC: nil
  value of $LC_TIME: nil
  value of $LANG: de_DE
  locale-coding-system: iso-latin-1
  default-enable-multibyte-characters: t

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

=========================================================================

Here is a short example what seems to be wrong:

;; first statement
(progn
  (make-local-variable 'track-mouse)
  (if (local-variable-p 'track-mouse)
      (message "okay")
    (error "Error"))

  (with-output-to-temp-buffer "*Help*"
    nil)
  (delete-other-windows))

;; second statement
(if (local-variable-p 'track-mouse)
    (message "okay")
  (error "Error"))

All the statements must be manually evaluated using C-x C-e
(eval-last-sexp), I was unable to reproduce this error using
eval-region yet).  It seems that the return to toplevel before the
second statement is essential to trigger that bug.

Normally I would expect that these statements completes without any
error message, however in my experiments the last statement yields the
error message.

This behaviour can hardly be normal, it is too scary ;-)

If I replace the builtin variable track-mouse by another variable
(tested with 'test) the above error is not triggered.

I also tested the current CVS version (21.3.50.1, updated some minutes
ago) and got the same behaviour in this emacs version.

Regards,

        Torsten

=========================================================================


Recent input:
v a r i a b l e SPC i s SPC s t i l l SPC m a r k e 
d SPC a s SPC l o c a l : M-q <M-return> C-x k <return> 
y e s <return> g <down-mouse-2> <mouse-2> <help-echo> 
<help-echo> t SPC C-u g SPC M-u q <up> <return> <return> 
t t n n n n n n n n n n <up> <return> SPC n n SPC n 
n n n n n n n <help-echo> <down-mouse-1> <mouse-1> 
M-u q g M-x r e p o <tab> r t <tab> <return>

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Re: Strange behaviour of track-mouse and make-local-variable

[Richard Stallman]

Does this change fix it?

*** tooltip.el.~1.23.~	Sun May 12 12:43:49 2002
--- tooltip.el	Mon May 27 16:11:40 2002
***************
*** 299,314 ****
  	  (tooltip-activate-mouse-motions nil))
  	(setq buffers (cdr buffers))))))
  
  
  (defun tooltip-activate-mouse-motions (activatep)
    "Activate/deactivate mouse motion events for the current buffer.
  ACTIVATEP non-nil means activate mouse motion events."
    (if activatep
        (progn
  	(make-local-variable 'track-mouse)
  	(setq track-mouse t))
!     (kill-local-variable 'track-mouse)))
! 
  
  (defun tooltip-mouse-motion (event)
    "Command handler for mouse movement events in `global-map'."
--- 299,319 ----
  	  (tooltip-activate-mouse-motions nil))
  	(setq buffers (cdr buffers))))))
  
+ (defvar tooltip-mouse-motions-active nil
+   "Locally t in a buffer if tooltip processing of mouse motion is enabled.")
  
  (defun tooltip-activate-mouse-motions (activatep)
    "Activate/deactivate mouse motion events for the current buffer.
  ACTIVATEP non-nil means activate mouse motion events."
    (if activatep
        (progn
+ 	(make-local-variable 'tooltip-mouse-motions-active)
+ 	(setq tooltip-mouse-motions-active t)
  	(make-local-variable 'track-mouse)
  	(setq track-mouse t))
!     (when tooltip-mouse-motions-active
!       (kill-local-variable 'tooltip-mouse-motions-active)
!       (kill-local-variable 'track-mouse))))
  
  (defun tooltip-mouse-motion (event)
    "Command handler for mouse movement events in `global-map'."

Re: Strange behaviour of track-mouse and make-local-variable

[Torsten Hilbrich]

Richard Stallman <rms@gnu.org> writes:

> Does this change fix it?

[patch for tooltip.el]

It fixes the bug I reported.  

I will have to do some more testing with my macro package, however the
code using the tooltips is still in development and it will take some
time.

I will report any other problems as I find them.

Thanks for your reply,

        Torsten