From 2b70333d7ecd533c7f5eb062f4f46126d2c1dbb3 Mon Sep 17 00:00:00 2001
From: John Cupitt <jcupitt@gmail.com>
Date: Sun, 25 Nov 2018 11:19:36 +0000
Subject: [PATCH] fix string truncation regression

buf_append was dropping the final byte
---
 libvips/iofuncs/buf.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/libvips/iofuncs/buf.c b/libvips/iofuncs/buf.c
index 08b9b5d4..c21b312a 100644
--- a/libvips/iofuncs/buf.c
+++ b/libvips/iofuncs/buf.c
@@ -275,11 +275,12 @@ vips_buf_appendns( VipsBuf *buf, const char *str, int sz )
 	 */
 	avail = buf->mx - buf->i - 4;
 
-	/* Amount we actually copy.
-	 */
 	cpy = VIPS_MIN( n, avail );
 
-	vips_strncpy( buf->base + buf->i, str, cpy );
+	/* Can't use vips_strncpy() here, we don't want to drop the end of the
+	 * string.
+	 */
+	strncpy( buf->base + buf->i, str, cpy );
 	buf->i += cpy;
 
 	if( buf->i >= buf->mx - 4 ) {