From 2b01f677796ba25e46464952731a52891ed56b7a Mon Sep 17 00:00:00 2001
From: zinovik <zinovik@openbsd.org>
Date: Sat, 31 Jul 2010 16:28:31 +0000
Subject: [PATCH] introduce macro SIZE_LEFT and function buf_grow() from
 OpenRCS

buf_grow() replaces macro BUF_GROW()

ok nicm@, ray@
---
 usr.bin/cvs/buf.c | 39 ++++++++++++++++++++++++---------------
 1 file changed, 24 insertions(+), 15 deletions(-)

diff --git a/usr.bin/cvs/buf.c b/usr.bin/cvs/buf.c
index 85a3ebe0b20..dd161245fd0 100644
--- a/usr.bin/cvs/buf.c
+++ b/usr.bin/cvs/buf.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: buf.c,v 1.76 2010/07/23 21:46:05 ray Exp $	*/
+/*	$OpenBSD: buf.c,v 1.77 2010/07/31 16:28:31 zinovik Exp $	*/
 /*
  * Copyright (c) 2003 Jean-Francois Brousseau <jfb@openbsd.org>
  * All rights reserved.
@@ -38,11 +38,6 @@
 #include "buf.h"
 
 #define BUF_INCR	128
-#define BUF_GROW(bp, len)						\
-	do {								\
-		b->cb_buf = xrealloc(b->cb_buf, 1, b->cb_size + len);	\
-		b->cb_size += len;					\
-	} while (0);
 
 struct buf {
 	u_char	*cb_buf;
@@ -50,6 +45,10 @@ struct buf {
 	size_t	 cb_len;
 };
 
+#define SIZE_LEFT(b)	(b->cb_size - b->cb_len)
+
+static void	buf_grow(BUF *, size_t);
+
 BUF *
 buf_alloc(size_t len)
 {
@@ -130,7 +129,7 @@ buf_putc(BUF *b, int c)
 
 	bp = b->cb_buf + b->cb_len;
 	if (bp == (b->cb_buf + b->cb_size)) {
-		BUF_GROW(b, BUF_INCR);
+		buf_grow(b, BUF_INCR);
 		bp = b->cb_buf + b->cb_len;
 	}
 	*bp = (u_char)c;
@@ -147,17 +146,14 @@ void
 buf_append(BUF *b, const void *data, size_t len)
 {
 	size_t left;
-	u_char *bp, *bep;
+	u_char *bp;
 
-	bp = b->cb_buf + b->cb_len;
-	bep = b->cb_buf + b->cb_size;
-	left = bep - bp;
+	left = SIZE_LEFT(b);
 
-	if (left < len) {
-		BUF_GROW(b, len - left);
-		bp = b->cb_buf + b->cb_len;
-	}
+	if (left < len)
+		buf_grow(b, len - left);
 
+	bp = b->cb_buf + b->cb_len;
 	memcpy(bp, data, len);
 	b->cb_len += len;
 }
@@ -241,3 +237,16 @@ buf_differ(const BUF *b1, const BUF *b2)
 
 	return (memcmp(b1->cb_buf, b2->cb_buf, b1->cb_len));
 }
+
+/*
+ * buf_grow()
+ *
+ * Grow the buffer <b> by <len> bytes.  The contents are unchanged by this
+ * operation regardless of the result.
+ */
+static void
+buf_grow(BUF *b, size_t len)
+{
+	b->cb_buf = xrealloc(b->cb_buf, 1, b->cb_size + len);
+	b->cb_size += len;
+}
-- 
2.20.1