From 91c2caa42aea33db5f1bcab2260546b915fac461 Mon Sep 17 00:00:00 2001
From: nicm <nicm@openbsd.org>
Date: Wed, 11 Jul 2018 06:51:39 +0000
Subject: [PATCH] Helper function to shorten history.

---
 usr.bin/tmux/grid.c | 19 ++++++++++++-------
 1 file changed, 12 insertions(+), 7 deletions(-)

diff --git a/usr.bin/tmux/grid.c b/usr.bin/tmux/grid.c
index d82317eae85..ec78d1e78f4 100644
--- a/usr.bin/tmux/grid.c
+++ b/usr.bin/tmux/grid.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: grid.c,v 1.85 2018/07/11 06:43:45 nicm Exp $ */
+/* $OpenBSD: grid.c,v 1.86 2018/07/11 06:51:39 nicm Exp $ */
 
 /*
  * Copyright (c) 2008 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -286,6 +286,15 @@ grid_compare(struct grid *ga, struct grid *gb)
 	return (0);
 }
 
+/* Trim lines from the history. */
+static void
+grid_trim_history(struct grid *gd, u_int ny)
+{
+	grid_free_lines(gd, 0, ny);
+	memmove(&gd->linedata[0], &gd->linedata[ny],
+	    (gd->hsize + gd->sy - ny) * (sizeof *gd->linedata));
+}
+
 /*
  * Collect lines from the history if at the limit. Free the top (oldest) 10%
  * and shift up.
@@ -308,9 +317,7 @@ grid_collect_history(struct grid *gd)
 	 * Free the lines from 0 to ny then move the remaining lines over
 	 * them.
 	 */
-	grid_free_lines(gd, 0, ny);
-	memmove(&gd->linedata[0], &gd->linedata[ny],
-	    (gd->hsize + gd->sy - ny) * (sizeof *gd->linedata));
+	grid_trim_history(gd, ny);
 
 	gd->hsize -= ny;
 	if (gd->hscrolled > gd->hsize)
@@ -340,9 +347,7 @@ grid_scroll_history(struct grid *gd, u_int bg)
 void
 grid_clear_history(struct grid *gd)
 {
-	grid_free_lines(gd, 0, gd->hsize);
-	memmove(&gd->linedata[0], &gd->linedata[gd->hsize],
-	    gd->sy * (sizeof *gd->linedata));
+	grid_trim_history(gd, gd->hsize);
 
 	gd->hscrolled = 0;
 	gd->hsize = 0;
-- 
2.20.1