diff_move_to(int dir, long count)
{
    int		idx;
    linenr_T	lnum = curwin->w_cursor.lnum;
    diff_T	*dp;

    idx = diff_buf_idx(curbuf);
    if (idx == DB_COUNT || curtab->tp_first_diff == NULL)
	return FAIL;

    if (curtab->tp_diff_invalid)
	ex_diffupdate(NULL);		// update after a big change

    if (curtab->tp_first_diff == NULL)		// no diffs today
	return FAIL;

    while (--count >= 0)
    {
	// Check if already before first diff.
	if (dir == BACKWARD && lnum <= curtab->tp_first_diff->df_lnum[idx])
	    break;

	for (dp = curtab->tp_first_diff; ; dp = dp->df_next)
	{
	    if (dp == NULL)
		break;
	    if ((dir == FORWARD && lnum < dp->df_lnum[idx])
		    || (dir == BACKWARD
			&& (dp->df_next == NULL
			    || lnum <= dp->df_next->df_lnum[idx])))
	    {
		lnum = dp->df_lnum[idx];
		break;
	    }
	}
    }

    // don't end up past the end of the file
    if (lnum > curbuf->b_ml.ml_line_count)
	lnum = curbuf->b_ml.ml_line_count;

    // When the cursor didn't move at all we fail.
    if (lnum == curwin->w_cursor.lnum)
	return FAIL;

    setpcmark();
    curwin->w_cursor.lnum = lnum;
    curwin->w_cursor.col = 0;

    return OK;
}
diff_move_to(int dir, long count)
{
    int		idx;
    linenr_T	lnum = curwin->w_cursor.lnum;
    diff_T	*dp;

    idx = diff_buf_idx(curbuf);
    if (idx == DB_COUNT || curtab->tp_first_diff == NULL)
	return FAIL;

    if (curtab->tp_diff_invalid)
	ex_diffupdate(NULL);		 

    if (curtab->tp_first_diff == NULL)		 
	return FAIL;

    while (--count >= 0)
    {
	 
	if (dir == BACKWARD && lnum <= curtab->tp_first_diff->df_lnum[idx])
	    break;

	for (dp = curtab->tp_first_diff; ; dp = dp->df_next)
	{
	    if (dp == NULL)
		break;
	    if ((dir == FORWARD && lnum < dp->df_lnum[idx])
		    || (dir == BACKWARD
			&& (dp->df_next == NULL
			    || lnum <= dp->df_next->df_lnum[idx])))
	    {
		lnum = dp->df_lnum[idx];
		break;
	    }
	}
    }

     
    if (lnum > curbuf->b_ml.ml_line_count)
	lnum = curbuf->b_ml.ml_line_count;

     
    if (lnum == curwin->w_cursor.lnum)
	return FAIL;

    setpcmark();
    curwin->w_cursor.lnum = lnum;
    curwin->w_cursor.col = 0;

    return OK;
}