From 59b94c42ec8cf63d774365688e4502a255cccf0f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=D0=97=D0=B0=20=D0=9B=D1=83=D0=BF=D0=BE=D0=B9?=
 <130570371+zalupoi@users.noreply.github.com>
Date: Wed, 12 Apr 2023 17:31:27 +0000
Subject: [PATCH] Fix RFC 7230 violation See
 https://github.com/nodejs/node/issues/47528 for more details

---
 src/WebResponses.cpp | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/src/WebResponses.cpp b/src/WebResponses.cpp
index a22e991aa..a5259076a 100644
--- a/src/WebResponses.cpp
+++ b/src/WebResponses.cpp
@@ -310,15 +310,14 @@ size_t AsyncAbstractResponse::_ack(AsyncWebServerRequest *request, size_t len, u
     size_t readLen = 0;
 
     if(_chunked){
-      // HTTP 1.1 allows leading zeros in chunk length. Or spaces may be added.
+      // HTTP 1.1 allows leading zeros in chunk length.
       // See RFC2616 sections 2, 3.6.1.
       readLen = _fillBufferAndProcessTemplates(buf+headLen+6, outLen - 8);
       if(readLen == RESPONSE_TRY_AGAIN){
           free(buf);
           return 0;
       }
-      outLen = sprintf((char*)buf+headLen, "%x", readLen) + headLen;
-      while(outLen < headLen + 4) buf[outLen++] = ' ';
+      outLen = sprintf((char*)buf+headLen, "%04x", readLen) + headLen;
       buf[outLen++] = '\r';
       buf[outLen++] = '\n';
       outLen += readLen;