From: Willy Tarreau <w@1wt.eu>
Date: Fri, 20 Oct 2017 16:21:49 +0000 (+0200)
Subject: MINOR: buffer: make bo_getblk_nc() not return 2 for a full buffer
X-Git-Tag: v1.8-dev3~23
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=0621da5f5bbd089e3562a412d7e73cf8971030b0;p=thirdparty%2Fhaproxy.git

MINOR: buffer: make bo_getblk_nc() not return 2 for a full buffer

Thus function returns the number of blocks. When a buffer is full and
properly aligned, buf->p loops back the beginning, and the test in the
code doesn't cover that specific case, so it returns two chunks, a full
one and an empty one. It's harmless but can sometimes have a small impact
on performance and definitely makes the code hard to debug.
---

diff --git a/include/common/buffer.h b/include/common/buffer.h
index 5ebf18cb35..9006c00953 100644
--- a/include/common/buffer.h
+++ b/include/common/buffer.h
@@ -532,7 +532,7 @@ static inline int bo_getblk_nc(struct buffer *buf, char **blk1, int *len1, char
 	if (unlikely(buf->o == 0))
 		return 0;
 
-	if (unlikely(buf->p - buf->o < buf->data)) {
+	if (unlikely(buf->p != buf->data && buf->p - buf->o < buf->data)) {
 		*blk1 = buf->p - buf->o + buf->size;
 		*len1 = buf->data + buf->size - *blk1;
 		*blk2 = buf->data;