===================================================================
RCS file: /cvsrepo/anoncvs/cvs/src/usr.bin/tmux/screen-write.c,v
retrieving revision 1.109
retrieving revision 1.110
diff -c -r1.109 -r1.110
*** src/usr.bin/tmux/screen-write.c	2017/02/08 16:45:18	1.109
--- src/usr.bin/tmux/screen-write.c	2017/02/08 17:31:09	1.110
***************
*** 1,4 ****
! /* $OpenBSD: screen-write.c,v 1.109 2017/02/08 16:45:18 nicm Exp $ */
  
  /*
   * Copyright (c) 2007 Nicholas Marriott <nicholas.marriott@gmail.com>
--- 1,4 ----
! /* $OpenBSD: screen-write.c,v 1.110 2017/02/08 17:31:09 nicm Exp $ */
  
  /*
   * Copyright (c) 2007 Nicholas Marriott <nicholas.marriott@gmail.com>
***************
*** 839,844 ****
--- 839,846 ----
  	if (rupper >= rlower)	/* cannot be one line */
  		return;
  
+ 	screen_write_collect_flush(ctx);
+ 
  	/* Cursor moves to top-left. */
  	s->cx = 0;
  	s->cy = 0;
***************
*** 854,860 ****
  	struct screen		*s = ctx->s;
  	struct grid		*gd = s->grid;
  	struct grid_line	*gl;
- 	struct tty_ctx		 ttyctx;
  
  	gl = &gd->linedata[gd->hsize + s->cy];
  	if (wrapped)
--- 856,861 ----
***************
*** 864,877 ****
  
  	if (s->cy == s->rlower) {
  		grid_view_scroll_region_up(gd, s->rupper, s->rlower);
- 
  		screen_write_collect_scroll(ctx);
! 		screen_write_initctx(ctx, &ttyctx);
! 		tty_write(tty_cmd_linefeed, &ttyctx);
  	} else if (s->cy < screen_size_y(s) - 1)
  		s->cy++;
  }
  
  /* Carriage return (cursor to start of line). */
  void
  screen_write_carriagereturn(struct screen_write_ctx *ctx)
--- 865,896 ----
  
  	if (s->cy == s->rlower) {
  		grid_view_scroll_region_up(gd, s->rupper, s->rlower);
  		screen_write_collect_scroll(ctx);
! 		ctx->scrolled++;
  	} else if (s->cy < screen_size_y(s) - 1)
  		s->cy++;
  }
  
+ /* Scroll up. */
+ void
+ screen_write_scrollup(struct screen_write_ctx *ctx, u_int lines)
+ {
+ 	struct screen	*s = ctx->s;
+ 	struct grid	*gd = s->grid;
+ 	u_int		 i;
+ 
+ 	if (lines == 0)
+ 		lines = 1;
+ 	else if (lines > s->rlower - s->rupper + 1)
+ 		lines = s->rlower - s->rupper + 1;
+ 
+ 	for (i = 0; i < lines; i++) {
+ 		grid_view_scroll_region_up(gd, s->rupper, s->rlower);
+ 		screen_write_collect_scroll(ctx);
+ 	}
+ 	ctx->scrolled += lines;
+ }
+ 
  /* Carriage return (cursor to start of line). */
  void
  screen_write_carriagereturn(struct screen_write_ctx *ctx)
***************
*** 1008,1013 ****
--- 1027,1044 ----
  	struct screen_write_collect_item	*ci, *tmp;
  	u_int					 y, cx, cy;
  	struct tty_ctx				 ttyctx;
+ 
+ 	if (ctx->scrolled != 0) {
+ 		log_debug("%s: scrolled %u (region %u-%u)", __func__,
+ 		    ctx->scrolled, s->rupper, s->rlower);
+ 		if (ctx->scrolled > s->rlower - s->rupper + 1)
+ 			ctx->scrolled = s->rlower - s->rupper + 1;
+ 
+ 		screen_write_initctx(ctx, &ttyctx);
+ 		ttyctx.num = ctx->scrolled;
+ 		tty_write(tty_cmd_scrollup, &ttyctx);
+ 	}
+ 	ctx->scrolled = 0;
  
  	cx = s->cx; cy = s->cy;
  	for (y = 0; y < screen_size_y(s); y++) {