Subject: bug#11210: Windows emacs 23.4.1: scroll-conservatively > 0 results in multiple cursors being displayed after scrolling

From: Bill Meier <[email-masked]>
Date: Tue, 10 Apr 2012 17:37:13 -0400

Ok: To answer various comments/questions in 1 EMail (and to summarize)_

> Could you perhaps try the latest pretest of Emacs 24.1, which is
> available from here:
>
>    http://alpha.gnu.org/gnu/emacs/pretest/windows/emacs-24.0.95-bin-i386.zip
>

Same effect.

Summary: OK in 23.3; NG in 23.4 & 24.0.95

-------------------
>> 6. If an EMacs frame is showing multiple EMacs windows, no cursor
>>      appears in the non-selected EMacs window.
>
> You mean, there's no empty rectangle in the non-selected windows?  Do
> you _ever_ see a cursor in non-selected windows on this system?
>

No (AFAICT).

Note: This might (or might not) be a different unrelated problem. I've 
just realized that this is true for my Emacs 23.3 also.

Also, as noted, changing cursor configuration (e.g., "blinking cursor") 
has no apparent effect.

If others using Windows 7 do see an empty rectangle in non-selected 
windows and/or are able to change the cursor config from within Emacs, 
then obviously there's something special/different about my configuration.

---------------------------------------
 >> abc
 >> 123
 >> |
 >>
 >>
 >> Strange ....
 >
 > Probably because of the different dimensions of the letters and the
 > digits.
 >
 > If you go to one of the 'a' characters and type "C-u C-x =", what font
 > does Emacs show as being used for this character?  Please also do the
 > same for '1' and see what it says then.
 >
 >

Actually: I see the same problem using 'def' (or seemingly any set of 
characters) instead of '123'.   :)

         character: a (97, #o141, #x61)
preferred charset: ascii (ASCII (ISO646 IRV))
        code point: 0x61
            syntax: w 	which means: word
          category: .:Base, a:ASCII, l:Latin, r:Roman
       buffer code: #x61
         file code: #x61 (encoded by coding system utf-8-dos)
           display: by this font (glyph code)
     uniscribe:-outline-Courier 
New-normal-normal-normal-mono-13-*-*-*-c-*-iso8859-1 (#x44)

Character code properties: customize what to show
   name: LATIN SMALL LETTER A
   general-category: Ll (Letter, Lowercase)

There are text properties here:
   fontified            t

-------------------------

The problem seems very "phase of the moon" related.

Only happens some fraction of the time (i.e. not on every down-arrow 
past the end of the buffer).

Seems definitely dependent upon the contents of the buffer.

I even got a fail (artifacts) once (even with scroll-conservatively set 
to 0) with a 24 line screen and a buffer of 50 lines of 'abc' and just 
repeatedly doing M-S-< followed by M-S->  .

---------------------------

My comment: maybe let this simmer for a while and see if anyone else 
reports a similar issue (or eventually decide the issue is something 
about my system).

(It's not the end of the world for me to run emacs with
'scroll-conservatively= 0')

Bill