From ee98c9419fd1dc67b66210cc373032a634085426 Mon Sep 17 00:00:00 2001
From: Aliaksandr Valialkin <valyala@gmail.com>
Date: Thu, 23 Jun 2016 17:43:05 +0300
Subject: [PATCH] Keep zero-length buffers in the pool

---
 pool.go | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/pool.go b/pool.go
index 9f3f5df..26d5c28 100644
--- a/pool.go
+++ b/pool.go
@@ -33,20 +33,24 @@ func (p *byteBufferPool) Acquire() *ByteBuffer {
 }
 
 func (p *byteBufferPool) Release(b *ByteBuffer) {
-	n := cap(b.B)
-	if n > maxSize {
+	bCap := cap(b.B)
+	if bCap > maxSize {
 		// Oversized buffer.
 		// Drop it.
 		return
 	}
-	if (n >> 2) > len(b.B) {
+	bLen := len(b.B)
+	if bLen > 0 && (bCap>>2) > bLen {
 		// Under-used buffer capacity.
 		// Drop it.
+		//
+		// Special case: do not drop zero-length buffers -
+		// this may be the result of Reset call.
 		return
 	}
 
 	b.B = b.B[:0]
-	idx := bitSize(n-1) >> minBitSize
+	idx := bitSize(bCap-1) >> minBitSize
 	p.pools[idx].Put(b)
 }