From 074553a1e41f93f84a791957818d8c842bdefdf6 Mon Sep 17 00:00:00 2001
From: Tim Edwards <tim@opencircuitdesign.com>
Date: Fri, 15 Sep 2017 21:12:44 -0400
Subject: [PATCH] Corrected backing store put/get in the case of obscuring
 windows. The OpenGL version was disabling backing store while any window
 obscures the layout;  the Cairo version was not.

---
 graphics/grTCairo3.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/graphics/grTCairo3.c b/graphics/grTCairo3.c
index 811f1678..4f8c8b8a 100644
--- a/graphics/grTCairo3.c
+++ b/graphics/grTCairo3.c
@@ -385,6 +385,12 @@ grtcairoPutBackingStore(MagWindow *w, Rect *area)
 
 	if (w->w_backingStore == (ClientData)0) return;
 
+	if (w->w_flags & WIND_OBSCURED)
+	{
+	    grtcairoFreeBackingStore(w);
+	    return;
+	}
+
 	xbot = area->r_xbot;
 	ybot = area->r_ybot;