From 116971053de3f0d38fe271ca34ddbbca94063b66 Mon Sep 17 00:00:00 2001
From: David du Colombier <0intro@gmail.com>
Date: Thu, 27 Nov 1997 00:00:00 +0000
Subject: [PATCH] Plan 9 from Bell Labs 1997-11-27

---
 port/devdraw.c | 14 ++++++++++----
 1 file changed, 10 insertions(+), 4 deletions(-)

diff --git a/port/devdraw.c b/port/devdraw.c
index 22e28bb3c90aa214ed7c4f2e6094bce20c0ce710..d0e1d729b24ff6f3dc325c35d0426cb15f305bd1 100644
--- a/port/devdraw.c
+++ b/port/devdraw.c
@@ -305,15 +305,21 @@ static
 void
 dstflush(int dstid, Memimage *dst, Rectangle r)
 {
+	Memlayer *l;
+
 	if(dstid == 0){
 		bbox(&flushrect, r);
 		return;
 	}
-	if(dst->layer == nil)
-		return;
-	if(dst->layer->screen->image->data != screenimage.data)
+	l = dst->layer;
+	if(l == nil)
 		return;
-	r = rectaddpt(r, dst->layer->delta);
+	do{
+		if(l->screen->image->data != screenimage.data)
+			return;
+		r = rectaddpt(r, l->delta);
+		l = l->screen->image->layer;
+	}while(l);
 	bbox(&flushrect, r);
 }