From 2d028db75a8a214557319d3f9898bfbcf384ddf7 Mon Sep 17 00:00:00 2001
From: Willy Tarreau <w@1wt.eu>
Date: Sun, 20 Sep 2009 22:56:25 +0200
Subject: [PATCH] [BUG] buffers: buffer_forward() must not always clear
 BF_OUT_EMPTY

This flag was unconditionally cleared, which is wrong because we
can enable forwarding on an empty buffer.
---
 include/proto/buffers.h | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/include/proto/buffers.h b/include/proto/buffers.h
index abaf5eeb5..432146c92 100644
--- a/include/proto/buffers.h
+++ b/include/proto/buffers.h
@@ -91,14 +91,17 @@ static inline void buffer_forward(struct buffer *buf, unsigned long bytes)
 
 	if (!bytes)
 		return;
-	buf->flags &= ~BF_OUT_EMPTY;
 	data_left = buf->l - buf->send_max;
 	if (data_left >= bytes) {
 		buf->send_max += bytes;
+		buf->flags &= ~BF_OUT_EMPTY;
 		return;
 	}
 
 	buf->send_max += data_left;
+	if (buf->send_max)
+		buf->flags &= ~BF_OUT_EMPTY;
+
 	if (buf->to_forward == BUF_INFINITE_FORWARD)
 		return;