From 2c52228fae92675f20d8b0f77fd23cd5cdc133ae Mon Sep 17 00:00:00 2001
From: Lee McDermott <lee@boards.local>
Date: Wed, 24 Nov 2021 19:06:36 +0000
Subject: [PATCH] Just use the incoming buffer if we're at zero, rather than
 copying

---
 Sources/NIOHTTP2/HTTP2FrameParser.swift | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/Sources/NIOHTTP2/HTTP2FrameParser.swift b/Sources/NIOHTTP2/HTTP2FrameParser.swift
index 2b00aa39..23e93b0a 100644
--- a/Sources/NIOHTTP2/HTTP2FrameParser.swift
+++ b/Sources/NIOHTTP2/HTTP2FrameParser.swift
@@ -64,7 +64,12 @@ struct HTTP2FrameDecoder {
         }
 
         mutating func accumulate(bytes: inout ByteBuffer) {
-            _ = self.unusedBytes.writeBuffer(&bytes)
+            if self.unusedBytes.readableBytes == 0 {
+                self.unusedBytes = bytes
+            }
+            else {
+                _ = self.unusedBytes.writeBuffer(&bytes)
+            }
         }
     }