From 674a0c3559b6fdb25e021f003384ada6bd906890 Mon Sep 17 00:00:00 2001
From: Martijn Dekker <martijn@inlv.org>
Date: Thu, 28 Jan 2021 06:32:42 +0000
Subject: [PATCH] Another lexical fix for here-documents (re: 6e515f1d)

OpenSUSE patch from:
https://build.opensuse.org/package/view_file/shells/ksh/ksh93-heredoc.dif

src/cmd/ksh93/sh/lex.c: here_copy():
- Do not potentially seek back a zero or negative length.
---
 src/cmd/ksh93/sh/lex.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/src/cmd/ksh93/sh/lex.c b/src/cmd/ksh93/sh/lex.c
index 90596e446..660878476 100644
--- a/src/cmd/ksh93/sh/lex.c
+++ b/src/cmd/ksh93/sh/lex.c
@@ -1891,6 +1891,8 @@ static int here_copy(Lex_t *lp,register struct ionod *iop)
 					sfputc(sp,'\\');
 				}
 			}
+			if(LEN < 1)
+				LEN = 1;
 			bufp = fcseek(-LEN);
 		}
 		else