From c5e42dffa16509049774fac628f5d013f50e4ae4 Mon Sep 17 00:00:00 2001
From: Jason Nelson <jason@carbonmade.com>
Date: Mon, 11 Jun 2018 12:31:50 -0700
Subject: [PATCH] Eliminate allocation reading BMP file header

---
 src/ImageSharp/Formats/Bmp/BmpDecoderCore.cs | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/src/ImageSharp/Formats/Bmp/BmpDecoderCore.cs b/src/ImageSharp/Formats/Bmp/BmpDecoderCore.cs
index 85461c0d2..7528f36bf 100644
--- a/src/ImageSharp/Formats/Bmp/BmpDecoderCore.cs
+++ b/src/ImageSharp/Formats/Bmp/BmpDecoderCore.cs
@@ -521,8 +521,11 @@ namespace SixLabors.ImageSharp.Formats.Bmp
         /// </summary>
         private void ReadFileHeader()
         {
+#if NETCOREAPP2_1
+            Span<byte> buffer = stackalloc byte[BmpFileHeader.Size];
+#else
             byte[] buffer = new byte[BmpFileHeader.Size];
-
+#endif
             this.stream.Read(buffer, 0, BmpFileHeader.Size);
 
             this.fileHeader = BmpFileHeader.Parse(buffer);