bug#8421: 23.3; Strange handling of mouse events in Nextstep/Cocoa port of Emacs23

[Konrad Podczeck]

Hello Jan,

first, thanks for your response, and excuse my answer being late.

I still can reproduce the phenomena with the latest nightly build of Emacs24, 
downloaded from http://emacsformacosx.com/builds on October 18.

Here the steps in more detail.

(1) Open Emacs from the finder.

(2) Via Apple-O, open some file, say A, and have the cursor in row 1 and column 
1.
 
(3) Via Apple-O, open another file, say B, and have the cursor in row 1 and 
column 1.

(4) Position the frame of B so that it has the same vertical coordinates on the 
screen as B, and horizontally overlaps the right half of the frame of A. The 
frame with B thus remains the active one, with the cursor position as given on 
(3).

(5) With mouse1, click on the frame of A at the cursor position there, so that 
the frame with A becomes active, then click somewhere on the visible part of 
the frame with B, but at vertical coordinate below row 1, so that, in 
particular, the frame with B becomes active again, and finally click somewhere 
in the frame with B, but at a vertical coordinate below that of the previous 
click and horizontal coordinate in the middle between column 1 and the 
horizontal coordinate of the previous click.

This gives me an unintended selection in the frame of B.

Starting Emacs from the command line with -Q, but otherwise proceeding the same 
way, gives the same.

With Emacs23, making a build by myself, I found something to make the phenomena 
to disappear:


I the file keyboard.c of the source code of Emacs23, lines 1495 to 1499 are:

 FOR_EACH_FRAME (tail, frame)
   {
     if (XFRAME (frame)->mouse_moved)
        return XFRAME (frame); 
  }

I have inserted a new line of code before the closing brace so as to have:

 FOR_EACH_FRAME (tail, frame)
   {
     if (XFRAME (frame)->mouse_moved)
        return XFRAME (frame); 
  return 0;
  }


Could this make any sense? I found it just by trial and error, and have no 
theoretical explanation. In any case, I worked with a Emacs23 build with this 
hack for several mounts now and didn't encounter any problem,

Thanks,

Konrad




Am 14.08.2011 um 11:13 schrieb Jan Djärv:

> Hello.
> 
> I can not reproduce this in Emacs 23.3 or the trunk.  Can you test the trunk? 
>  Can you reproduce this when starting Emacs with -Q?
> 
>       Jan D.
> 
> 
> Konrad Podczeck skrev 2011-04-04 16:46:
>> I observe the following.
>> 
>> Start Emacs and then open two files one after the other, which makes them to 
>> appear in two separate frames, say A and B. Position the two frames so that 
>> they overlap, say so that the respective active frame covers half of the 
>> other frame. Let frame A be the active one and position the cursor so that 
>> on its line there is text to the left as well as to the right. Let me call 
>> this cursor position x. Now click into frame B to make it active, and the 
>> click again into frame A first at a place whose column is to the left of 
>> that of  x, and then a second time to a place whose column is to the the 
>> right of that of x. This yields an unintended selection in frame A.
>> 
>> This behaviour is annoying if one works with several frames at the same time.
>> 
>> 
>> 
>> In GNU Emacs 23.3.1 (x86_64-apple-darwin, NS apple-appkit-1038.35)
>> of 2011-03-10 on black.porkrind.org
>> Windowing system distributor `Apple', version 10.3.1038
>> configured using `configure  '--host=x86_64-apple-darwin' 
>> '--build=i686-apple-darwin' '--with-ns' 'build_alias=i686-apple-darwin' 
>> 'host_alias=x86_64-apple-darwin' 'CC=gcc -mmacosx-version-min=10.5''
>> 
>> 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: nil
>>   value of $XMODIFIERS: nil
>>   locale-coding-system: nil
>>   default enable-multibyte-characters: t
>> 
>> Major mode: Fundamental
>> 
>> Minor modes in effect:
>>   tooltip-mode: t
>>   mouse-wheel-mode: t
>>   menu-bar-mode: t
>>   file-name-shadow-mode: t
>>   global-font-lock-mode: t
>>   blink-cursor-mode: t
>>   auto-encryption-mode: t
>>   auto-compression-mode: t
>>   line-number-mode: t
>>   transient-mark-mode: t
>> 
>> Recent input:
>> <help-echo>  <help-echo>  <menu-bar>  <help-menu>  <se
>> nd-emacs-bug-report>
>> 
>> Recent messages:
>> For information about GNU Emacs and the GNU system, type C-h C-a.
>> 
>> Load-path shadows:
>> None found.
>> 
>> Features:
>> (shadow sort mail-extr message ecomplete rfc822 mml mml-sec
>> password-cache mm-decode mm-bodies mm-encode mailcap mail-parse rfc2231
>> rfc2047 rfc2045 qp ietf-drums mailabbrev nnheader gnus-util netrc
>> time-date mm-util mail-prsvr gmm-utils wid-edit mailheader canlock sha1
>> hex-util hashcash mail-utils emacsbug tooltip ediff-hook vc-hooks
>> lisp-float-type mwheel ns-win easymenu tool-bar dnd fontset image fringe
>> lisp-mode register page menu-bar rfn-eshadow timer select scroll-bar
>> mldrag 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 loaddefs button minibuffer faces cus-face files text-properties
>> overlay md5 base64 format env code-pages mule custom widget
>> hashtable-print-readable backquote make-network-process ns multi-tty
>> emacs)
>> 
>> 
>