From 80c4320260a7e9b4a0152b24deefd4ddf4c66118 Mon Sep 17 00:00:00 2001
From: pfg <pfg@FreeBSD.org>
Date: Wed, 1 Jun 2016 16:53:02 +0000
Subject: [PATCH] sed(1): Fix a mismatch and sync with the OpenBSD's commit.

This was causing some strange behaviour.

Reported by:	olivier
Obtained from:	OpenBSD (CVS rev. 1.28)
---
 usr.bin/sed/process.c | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/usr.bin/sed/process.c b/usr.bin/sed/process.c
index 5c883c4229ff..b70a492349ad 100644
--- a/usr.bin/sed/process.c
+++ b/usr.bin/sed/process.c
@@ -394,7 +394,7 @@ substitute(struct s_command *cp)
 					linenum, fname, cp->u.s->maxbref);
 		}
 	}
-	if (!regexec_e(re, s, 0, 0, 0, psl))
+	if (!regexec_e(re, ps, 0, 0, 0, psl))
 		return (0);
 
 	SS.len = 0;				/* Clean substitute space. */
@@ -404,7 +404,7 @@ substitute(struct s_command *cp)
 
 	do {
 		/* Copy the leading retained string. */
-		if (n <= 1 && match[0].rm_so - le)
+		if (n <= 1 && (match[0].rm_so > le))
 			cspace(&SS, s, match[0].rm_so - le, APPEND);
 
 		/* Skip zero-length matches right after other matches. */
@@ -425,8 +425,8 @@ substitute(struct s_command *cp)
 		}
 
 		/* Move past this match. */
-		s += (match[0].rm_eo - le);
-		slen -= (match[0].rm_eo - le);
+		s = ps + match[0].rm_eo;
+		slen = psl - match[0].rm_eo;
 		le = match[0].rm_eo;
 
 		/*
@@ -446,7 +446,8 @@ substitute(struct s_command *cp)
 		} else
 			lastempty = 0;
 
-	} while (n >= 0 && slen >= 0 && regexec_e(re, ps, 0, 0, le, psl));
+	} while (n >= 0 && slen >= 0 &&
+	    regexec_e(re, ps, REG_NOTBOL, 0, le, psl));
 
 	/* Did not find the requested number of matches. */
 	if (n > 1)