vertical-motion behavior change

vertical-motion behavior change

[Dan Nicolaescu]

Sometime in the past month the behavior of (vertical-motion 0) has
changed. 
For sources checked out of CVS on Nov 1st, (vertical-motion 0) would
move the point to the beginning of the line. 
For the current CVS sources (vertical-motion 0) would not move the
point. 

term.el relies on the old behavior in a few places, and not it does
not work correctly anymore...

Is this change intentional, or is an unwanted side effect? 

   --dan

Re: vertical-motion behavior change

[Peter Heslin]

On 2004-12-03, Dan Nicolaescu <dann@godzilla.ics.uci.edu> wrote:
> 
>  Sometime in the past month the behavior of (vertical-motion 0) has
>  changed. 
>  For sources checked out of CVS on Nov 1st, (vertical-motion 0) would
>  move the point to the beginning of the line. 
>  For the current CVS sources (vertical-motion 0) would not move the
>  point. 
> 
>  term.el relies on the old behavior in a few places, and not it does
>  not work correctly anymore...

This would also explain why screen-lines.el (not part of Emacs)
stopped working correctly at about that point in time.

>  Is this change intentional, or is an unwanted side effect? 

There are other packages that rely on the old behavior, and the
doc-string might have been interpreted to guarantee it:

    Move point to start of the screen line LINES lines down.

To me, that implies that a value of zero for LINES should move point
to the start of the current line.

Peter

Re: vertical-motion behavior change

[Richard Stallman]

Does this change give correct results?

*** indent.c	23 Nov 2004 11:44:50 -0500	1.172
--- indent.c	06 Dec 2004 16:09:41 -0500	
***************
*** 2092,2099 ****
  	move_it_by_lines (&it, -1, 0);
  
        it.vpos = 0;
!       if (XINT (lines) != 0)
! 	move_it_by_lines (&it, XINT (lines), 0);
  
        SET_PT_BOTH (IT_CHARPOS (it), IT_BYTEPOS (it));
      }
--- 2092,2098 ----
  	move_it_by_lines (&it, -1, 0);
  
        it.vpos = 0;
!       move_it_by_lines (&it, XINT (lines), 0);
  
        SET_PT_BOTH (IT_CHARPOS (it), IT_BYTEPOS (it));
      }

Re: vertical-motion behavior change

[Peter Heslin]

On 2004-12-07, Richard Stallman <rms@gnu.org> wrote:
>  Does this change give correct results?

Yes, that fixes the problem I was having.  Thanks.

Peter

Re: vertical-motion behavior change

[Dan Nicolaescu]

Richard Stallman <rms@gnu.org> writes:

  > Does this change give correct results?

Yes, it does.