From 44c1ad58b19c25934fdb0b58db63709bda3f27f9 Mon Sep 17 00:00:00 2001
From: Brian Popow <popow@gmx.de>
Date: Sat, 21 May 2022 22:31:18 +0200
Subject: [PATCH] Use flag to indicate if JFIF marker is present (invalid
 markers also count)

---
 src/ImageSharp/Formats/Jpeg/JpegDecoderCore.cs | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/src/ImageSharp/Formats/Jpeg/JpegDecoderCore.cs b/src/ImageSharp/Formats/Jpeg/JpegDecoderCore.cs
index e1e6d5d6e9..1e7f5a92e3 100644
--- a/src/ImageSharp/Formats/Jpeg/JpegDecoderCore.cs
+++ b/src/ImageSharp/Formats/Jpeg/JpegDecoderCore.cs
@@ -90,6 +90,11 @@ namespace SixLabors.ImageSharp.Formats.Jpeg
         /// </summary>
         private JFifMarker jFif;
 
+        /// <summary>
+        /// Whether the image has a JFIF marker. This is needed to determine, if the colorspace is YCbCr.
+        /// </summary>
+        private bool hasJFif;
+
         /// <summary>
         /// Contains information about the Adobe marker.
         /// </summary>
@@ -519,7 +524,7 @@ namespace SixLabors.ImageSharp.Formats.Jpeg
                     return JpegColorSpace.RGB;
                 }
 
-                if (!this.jFif.Equals(default))
+                if (this.hasJFif)
                 {
                     // JFIF implies YCbCr.
                     return JpegColorSpace.YCbCr;
@@ -721,6 +726,8 @@ namespace SixLabors.ImageSharp.Formats.Jpeg
         /// <param name="remaining">The remaining bytes in the segment block.</param>
         private void ProcessApplicationHeaderMarker(BufferedReadStream stream, int remaining)
         {
+            this.hasJFif = true;
+
             // We can only decode JFif identifiers.
             // Some images contain multiple JFIF markers (Issue 1932) so we check to see
             // if it's already been read.