From 9310d452c9cd1dbff4d87557001634ed8d624ed4 Mon Sep 17 00:00:00 2001
From: "M. Warner Losh" <wlosh@netflix.com>
Date: Sun, 2 Jun 2019 15:23:06 -0600
Subject: [PATCH] Apply the following from FreeBSD / OpenBSD:

323965 | imp | 2017-09-23 23:04:06 -0600 (Sat, 23 Sep 2017) | 8 lines

Don't display empty error context.

Context extraction didn't handle this case and showed uninitialized memory.

Obtained from: OpenBSD lib.c 1.21
Sponsored by: Netflix
Differential Revision: https://reviews.freebsd.org/D12379
---
 lib.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib.c b/lib.c
index 7e83439..864326e 100644
--- a/lib.c
+++ b/lib.c
@@ -647,7 +647,7 @@ void eprint(void)	/* try to print context around error */
 	static int been_here = 0;
 	extern char ebuf[], *ep;
 
-	if (compile_time == 2 || compile_time == 0 || been_here++ > 0)
+	if (compile_time == 2 || compile_time == 0 || been_here++ > 0 || ebuf == ep)
 		return;
 	if (ebuf == ep)
 		return;