From 5dcc25f5ebba3356b6fc9aa4369d5e43c0759743 Mon Sep 17 00:00:00 2001
From: Peter Evans <peter@modul8r.com>
Date: Mon, 12 Mar 2018 00:33:22 -0500
Subject: [PATCH] Reject -1 rows and columns

---
 src/apple2.lores.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/apple2.lores.c b/src/apple2.lores.c
index fa0a456..d19306f 100644
--- a/src/apple2.lores.c
+++ b/src/apple2.lores.c
@@ -54,6 +54,10 @@ apple2_lores_draw(apple2 *mach, size_t addr)
     int row = apple2_text_row(addr),
         col = apple2_text_col(addr);
 
+    if (row == -1 || col == -1) {
+        return;
+    }
+
     // In low-resolution mode, the row number is analagous to the text
     // row number, like so:
     row *= 2;