Re: [az@ftc.ru: hl-line-mode conflicts with scroll-margin]

[storm@cua.dk (Kim F. Storm)]

Juri Linkov <juri@jurta.org> writes:

> storm@cua.dk (Kim F. Storm) writes:
> > The following patch solves the problem.
> 
> Here is another related bug report for you :-)
> 
> If scroll-margin is not 0 and font-lock-mode is turned on, i.e.
> 
> (progn
>   (setq scroll-margin 5)
>   (global-font-lock-mode))
> 
> then after moving the cursor down until it reaches the fifth line from
> the bottom of the window the cursor is placed in the center of the window
> where it starts jumping forth and back: after 1 second it moves to the
> end of the line, and after another 1 second moves to the beginning
> of the following line.
> 
> This bug can be reproduced on GNU/Linux in Emacs versions starting
> at least from 21.3.


Ok, try this patch:

*** xdisp.c	30 May 2004 23:13:12 +0200	1.892
--- xdisp.c	15 Jun 2004 00:31:01 +0200	
***************
*** 12542,12550 ****
  	 position.  */
        if (pt_row)
  	{
! 	  w->cursor.vpos -= MATRIX_ROW_VPOS (first_reusable_row,
! 					     w->current_matrix);
! 	  w->cursor.y -= first_reusable_row->y;
  	}
  
        /* Scroll the display.  */
--- 12542,12549 ----
  	 position.  */
        if (pt_row)
  	{
! 	  w->cursor.vpos -= nrows_scrolled;
! 	  w->cursor.y -= first_reusable_row->y - start_row->y;
  	}
  
        /* Scroll the display.  */
***************
*** 12589,12594 ****
--- 12588,12616 ----
        for (row -= nrows_scrolled; row < bottom_row; ++row)
  	row->enabled_p = 0;
  
+       /* Point may have moved to a different line, so we cannot assume that
+ 	 the previous cursor position is valid; locate the correct row.  */
+       if (pt_row)
+ 	{
+ 	  for (row = MATRIX_ROW (w->current_matrix, w->cursor.vpos);
+ 	       row < bottom_row && PT >= MATRIX_ROW_END_CHARPOS (row);
+ 	       row++)
+ 	    {
+ 	      w->cursor.vpos++;
+ 	      w->cursor.y = row->y;
+ 	    }
+ 	  if (row < bottom_row)
+ 	    {
+ 	      struct glyph *glyph = row->glyphs[TEXT_AREA] + w->cursor.hpos;
+ 	      while (glyph->charpos < PT)
+ 		{
+ 		  w->cursor.hpos++;
+ 		  w->cursor.x += glyph->pixel_width;
+ 		  glyph++;
+ 		}
+ 	    }
+ 	}
+ 
        /* Adjust window end.  A null value of last_text_row means that
  	 the window end is in reused rows which in turn means that
  	 only its vpos can have changed.  */

-- 
Kim F. Storm <storm@cua.dk> http://www.cua.dk