===================================================================
RCS file: /cvsrepo/anoncvs/cvs/src/usr.bin/tmux/mode-tree.c,v
retrieving revision 1.9
retrieving revision 1.10
diff -c -r1.9 -r1.10
*** src/usr.bin/tmux/mode-tree.c	2017/08/23 09:39:11	1.9
--- src/usr.bin/tmux/mode-tree.c	2017/08/27 09:08:36	1.10
***************
*** 1,4 ****
! /* $OpenBSD: mode-tree.c,v 1.9 2017/08/23 09:39:11 nicm Exp $ */
  
  /*
   * Copyright (c) 2017 Nicholas Marriott <nicholas.marriott@gmail.com>
--- 1,4 ----
! /* $OpenBSD: mode-tree.c,v 1.10 2017/08/27 09:08:36 nicm Exp $ */
  
  /*
   * Copyright (c) 2017 Nicholas Marriott <nicholas.marriott@gmail.com>
***************
*** 870,875 ****
--- 870,884 ----
  	case 'v':
  		mtd->preview = !mtd->preview;
  		mode_tree_build(mtd);
+ 
+ 		/*
+ 		 * If the current line would now be off screen now the preview
+ 		 * is on, reset the the offset to the last visible line.
+ 		 */
+ 		if (mtd->preview && mtd->current > mtd->height - 1) {
+ 			mtd->offset = mtd->current - mtd->height;
+ 			mtd->current--;
+ 		}
  		break;
  	}
  	return (0);