From: Willy Tarreau <w@1wt.eu>
Date: Mon, 28 Nov 2011 12:40:49 +0000 (+0100)
Subject: BUG: buffers: don't return a negative value on buffer_total_space_res()
X-Git-Tag: v1.5-dev8~76
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=fe4b1f9dc03f1c62dd9d45f18d99cf9d9919e11f;p=thirdparty%2Fhaproxy.git

BUG: buffers: don't return a negative value on buffer_total_space_res()

In commit 4b517ca93aaaead8aa6143aa2836dc96417653c6 (MEDIUM: buffers:
add some new primitives and rework existing ones), we forgot to check
if buffer_max_len() < l.

No backport is needed.
---

diff --git a/include/proto/buffers.h b/include/proto/buffers.h
index b241a569fb..0a2da34984 100644
--- a/include/proto/buffers.h
+++ b/include/proto/buffers.h
@@ -103,11 +103,13 @@ static inline int buffer_total_space(const struct buffer *buf)
 }
 
 /* Return the maximum amount of bytes that can be written into the buffer,
- * excluding the reserved space, which is preserved.
+ * excluding the reserved space, which is preserved. 0 may be returned if
+ * the reserved space was already reached or used.
  */
 static inline int buffer_total_space_res(const struct buffer *buf)
 {
-	return buffer_max_len(buf) - buf->l;
+	int len = buffer_max_len(buf) - buf->l;
+	return len < 0 ? 0 : len;
 }
 
 /* Returns the number of contiguous bytes between <start> and <start>+<count>,