From 17c90a7e17102041c315ef2449c7e3e04e937da7 Mon Sep 17 00:00:00 2001
From: Artyom Tarasov <artar94@users.noreply.github.com>
Date: Thu, 14 May 2020 20:47:26 +0300
Subject: [PATCH] Fix for https://github.com/dotnet/aspnetcore/issues/17277
 (#21819)

Fixed adding a string with a large number of trailing zeros to StringBuilder, which sometimes caused the thread to hang
---
 .../SpaServices.Extensions/src/Util/EventedStreamReader.cs      | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/Middleware/SpaServices.Extensions/src/Util/EventedStreamReader.cs b/src/Middleware/SpaServices.Extensions/src/Util/EventedStreamReader.cs
index aafd630853..8cb33787a5 100644
--- a/src/Middleware/SpaServices.Extensions/src/Util/EventedStreamReader.cs
+++ b/src/Middleware/SpaServices.Extensions/src/Util/EventedStreamReader.cs
@@ -111,7 +111,7 @@ namespace Microsoft.AspNetCore.NodeServices.Util
                 // get the rest
                 if (lineBreakPos < 0 && startPos < chunkLength)
                 {
-                    _linesBuffer.Append(buf, startPos, chunkLength);
+                    _linesBuffer.Append(buf, startPos, chunkLength - startPos);
                 }
             }
         }