From bc6178167f92d8c77df8c70901b3cd5529542944 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?G=C3=BCnther=20Foidl?= <gue@korporal.at>
Date: Mon, 13 Mar 2023 21:03:24 +0100
Subject: [PATCH] Fixed bugs

---
 .../Decoder/ArithmeticScanDecoder.cs           | 18 +++++++-----------
 src/ImageSharp/Primitives/Rectangle.cs         |  2 +-
 2 files changed, 8 insertions(+), 12 deletions(-)

diff --git a/src/ImageSharp/Formats/Jpeg/Components/Decoder/ArithmeticScanDecoder.cs b/src/ImageSharp/Formats/Jpeg/Components/Decoder/ArithmeticScanDecoder.cs
index 423e56378a..73de430730 100644
--- a/src/ImageSharp/Formats/Jpeg/Components/Decoder/ArithmeticScanDecoder.cs
+++ b/src/ImageSharp/Formats/Jpeg/Components/Decoder/ArithmeticScanDecoder.cs
@@ -53,6 +53,8 @@ internal class ArithmeticScanDecoder : IJpegScanDecoder
 
     private ArithmeticDecodingTable[] acDecodingTables;
 
+    private static readonly byte[] FixedBin = { 113, 0, 0, 0 };
+
     private readonly CancellationToken cancellationToken;
 
     private static readonly int[] ArithmeticTable =
@@ -229,13 +231,7 @@ internal class ArithmeticScanDecoder : IJpegScanDecoder
         }
     }
 
-    private static ref byte GetFixedBinReference()
-    {
-        // This uses C#'s optimization to refer to the static data segment of the assembly.
-        // No allocation occurs.
-        ReadOnlySpan<byte> fixedBin = new byte[] { 113, 0, 0, 0 };
-        return ref MemoryMarshal.GetReference(fixedBin);
-    }
+    private static ref byte GetFixedBinReference() => ref MemoryMarshal.GetArrayDataReference(FixedBin);
 
     /// <summary>
     /// Decodes the entropy coded data.
@@ -765,7 +761,7 @@ internal class ArithmeticScanDecoder : IJpegScanDecoder
                     }
                 }
 
-                v += 1;
+                v++;
                 if (sign != 0)
                 {
                     v = -v;
@@ -860,7 +856,7 @@ internal class ArithmeticScanDecoder : IJpegScanDecoder
                     }
                 }
 
-                v += 1;
+                v++;
                 if (sign != 0)
                 {
                     v = -v;
@@ -1016,7 +1012,7 @@ internal class ArithmeticScanDecoder : IJpegScanDecoder
                 }
             }
 
-            v += 1;
+            v++;
             if (sign != 0)
             {
                 v = -v;
@@ -1086,7 +1082,7 @@ internal class ArithmeticScanDecoder : IJpegScanDecoder
                 }
             }
 
-            v += 1;
+            v++;
             if (sign != 0)
             {
                 v = -v;
diff --git a/src/ImageSharp/Primitives/Rectangle.cs b/src/ImageSharp/Primitives/Rectangle.cs
index 2f0df3574e..e2ae5071ef 100644
--- a/src/ImageSharp/Primitives/Rectangle.cs
+++ b/src/ImageSharp/Primitives/Rectangle.cs
@@ -195,7 +195,7 @@ public struct Rectangle : IEquatable<Rectangle>
     /// <param name="rectangle">The rectangle.</param>
     /// <returns>The <see cref="Point"/>.</returns>
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
-    public static Point Center(Rectangle rectangle) => new(rectangle.Left + (rectangle.Width & 1), rectangle.Top + (rectangle.Height & 1));     // & 1 is bit-hack for / 2
+    public static Point Center(Rectangle rectangle) => new(rectangle.Left + (rectangle.Width >> 1), rectangle.Top + (rectangle.Height >> 1));     // >> 1 is bit-hack for / 2
 
     /// <summary>
     /// Creates a rectangle that represents the intersection between <paramref name="a"/> and