Throw NotSupportedException for arithmetic coding and lossless jpeg's

src/ImageSharp/Formats/Jpeg/JpegConstants.cs

@@ -133,6 +133,11 @@ namespace SixLabors.ImageSharp.Formats.Jpeg
             /// </summary>
             public const byte APP15 = 0xEF;
 
+            /// <summary>
+            /// Define arithmetic coding conditioning marker.
+            /// </summary>
+            public const byte DAC = 0xCC;
+
             /// <summary>
             /// The text comment marker
             /// </summary>
@@ -173,6 +178,46 @@ namespace SixLabors.ImageSharp.Formats.Jpeg
             /// </summary>
             public const byte SOF2 = 0xC2;
 
+            /// <summary>
+            /// Start of Frame marker, non differential lossless, Huffman coding.
+            /// </summary>
+            public const byte SOF3 = 0xC3;
+
+            /// <summary>
+            /// Start of Frame marker, differential lossless, Huffman coding.
+            /// </summary>
+            public const byte SOF7 = 0xC7;
+
+            /// <summary>
+            /// Start of Frame marker, non-differential, arithmetic coding, Extended sequential DCT.
+            /// </summary>
+            public const byte SOF9 = 0xC9;
+
+            /// <summary>
+            /// Start of Frame marker, non-differential, arithmetic coding, Progressive DCT.
+            /// </summary>
+            public const byte SOF10 = 0xCA;
+
+            /// <summary>
+            /// Start of Frame marker, non-differential, arithmetic coding, Lossless (sequential).
+            /// </summary>
+            public const byte SOF11 = 0xCB;
+
+            /// <summary>
+            /// Start of Frame marker, differential, arithmetic coding, Differential sequential DCT.
+            /// </summary>
+            public const byte SOF13 = 0xCD;
+
+            /// <summary>
+            /// Start of Frame marker, differential, arithmetic coding, Differential progressive DCT.
+            /// </summary>
+            public const byte SOF14 = 0xCE;
+
+            /// <summary>
+            /// Start of Frame marker, differential, arithmetic coding, Differential lossless (sequential).
+            /// </summary>
+            public const byte SOF15 = 0xCF;
+
             /// <summary>
             /// Define Huffman Table(s)
             /// <remarks>

src/ImageSharp/Formats/Jpeg/JpegDecoderCore.cs

@@ -247,6 +247,20 @@ namespace SixLabors.ImageSharp.Formats.Jpeg
                             this.ProcessStartOfFrameMarker(stream, remaining, fileMarker, metadataOnly);
                             break;
 
+                        case JpegConstants.Markers.SOF3:
+                        case JpegConstants.Markers.SOF7:
+                            JpegThrowHelper.ThrowNotSupportedException("Decoding lossless jpeg files is not supported.");
+                            break;
+
+                        case JpegConstants.Markers.SOF9:
+                        case JpegConstants.Markers.SOF10:
+                        case JpegConstants.Markers.SOF11:
+                        case JpegConstants.Markers.SOF13:
+                        case JpegConstants.Markers.SOF14:
+                        case JpegConstants.Markers.SOF15:
+                            JpegThrowHelper.ThrowNotSupportedException("Decoding jpeg files with arithmetic coding is not supported.");
+                            break;
+
                         case JpegConstants.Markers.SOS:
                             if (!metadataOnly)
                             {
@@ -326,6 +340,10 @@ namespace SixLabors.ImageSharp.Formats.Jpeg
                         case JpegConstants.Markers.COM:
                             stream.Skip(remaining);
                             break;
+
+                        case JpegConstants.Markers.DAC:
+                            JpegThrowHelper.ThrowNotSupportedException("Decoding jpeg files with arithmetic coding is not supported.");
+                            break;
                     }
                 }
 

src/ImageSharp/Formats/Jpeg/JpegThrowHelper.cs

@@ -8,6 +8,13 @@ namespace SixLabors.ImageSharp.Formats.Jpeg
 {
     internal static class JpegThrowHelper
     {
+        /// <summary>
+        /// Cold path optimization for throwing <see cref="NotSupportedException"/>'s.
+        /// </summary>
+        /// <param name="errorMessage">The error message for the exception.</param>
+        [MethodImpl(InliningOptions.ColdPath)]
+        public static void ThrowNotSupportedException(string errorMessage) => throw new NotSupportedException(errorMessage);
+
         /// <summary>
         /// Cold path optimization for throwing <see cref="InvalidImageContentException"/>'s.
         /// </summary>

tests/ImageSharp.Tests/Formats/Jpg/JpegDecoderTests.cs

@@ -74,7 +74,7 @@ namespace SixLabors.ImageSharp.Tests.Formats.Jpg
             byte[] bytes = TestFile.Create(TestImages.Jpeg.Progressive.Progress).Bytes;
             using var ms = new MemoryStream(bytes);
             using var bufferedStream = new BufferedReadStream(Configuration.Default, ms);
-            var decoder = new JpegDecoderCore(Configuration.Default, new JpegDecoder());
+            using var decoder = new JpegDecoderCore(Configuration.Default, new JpegDecoder());
             using Image<Rgba32> image = decoder.Decode<Rgba32>(bufferedStream, cancellationToken: default);
 
             // I don't know why these numbers are different. All I know is that the decoder works
@@ -174,6 +174,19 @@ namespace SixLabors.ImageSharp.Tests.Formats.Jpg
             await Assert.ThrowsAsync<TaskCanceledException>(async () => await Image.IdentifyAsync(config, "someFakeFile", cts.Token));
         }
 
+        [Theory]
+        [WithFile(TestImages.Jpeg.Baseline.ArithmeticCoding, PixelTypes.Rgba32)]
+        [WithFile(TestImages.Jpeg.Baseline.ArithmeticCodingProgressive, PixelTypes.Rgba32)]
+        [WithFile(TestImages.Jpeg.Baseline.Lossless, PixelTypes.Rgba32)]
+        public void ThrowsNotSupported_WithUnsupportedJpegs<TPixel>(TestImageProvider<TPixel> provider)
+            where TPixel : unmanaged, IPixel<TPixel>
+        {
+            Assert.Throws<NotSupportedException>(() =>
+            {
+                using Image<TPixel> image = provider.GetImage(JpegDecoder);
+            });
+        }
+
         // https://github.com/SixLabors/ImageSharp/pull/1732
         [Theory]
         [WithFile(TestImages.Jpeg.Issues.WrongColorSpace, PixelTypes.Rgba32)]

tests/ImageSharp.Tests/TestImages.cs

@@ -200,6 +200,9 @@ namespace SixLabors.ImageSharp.Tests
                 public const string App13WithEmptyIptc = "Jpg/baseline/iptc-psAPP13-wIPTCempty.jpg";
                 public const string HistogramEqImage = "Jpg/baseline/640px-Unequalized_Hawkes_Bay_NZ.jpg";
                 public const string ForestBridgeDifferentComponentsQuality = "Jpg/baseline/forest_bridge.jpg";
+                public const string ArithmeticCoding = "Jpg/baseline/arithmetic_coding.jpg";
+                public const string ArithmeticCodingProgressive = "Jpg/baseline/arithmetic_progressive.jpg";
+                public const string Lossless = "Jpg/baseline/lossless.jpg";
 
                 public static readonly string[] All =
                 {

tests/Images/Input/Jpg/baseline/arithmetic_coding.jpg

@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:fec7012d9ae52a12c4617fd7526e506feee812fc67e923a76b2ca88c95f7a538
+size 3111

tests/Images/Input/Jpg/baseline/arithmetic_progressive.jpg

@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:3af237c172248d39c7b82c879de3d162e4dafaf36dc298add210740843edd33f
+size 3129

tests/Images/Input/Jpg/baseline/lossless.jpg

@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:8937e245885e1f280e1843ad48a4349ec1a3f71f86c954229cd44160aeeaaac4
+size 209584