fixed #178

src/ImageSharp/Formats/Jpeg/GolangPort/Components/Decoder/OrigJpegScanDecoder.cs

@@ -605,12 +605,7 @@ namespace SixLabors.ImageSharp.Formats.Jpeg.GolangPort.Components.Decoder
                         return;
                     }
 
-                    if (zig > this.zigEnd)
-                    {
-                        throw new ImageFormatException($"Too many coefficients {zig} > {this.zigEnd}");
-                    }
-
-                    if (z != 0)
+                    if (z != 0 && zig <= this.zigEnd)
                     {
                         // b[Unzig[zig]] = z;
                         Block8x8.SetScalarAt(b, this.pointers.Unzig[zig], (short)z);

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

@@ -45,7 +45,7 @@ namespace SixLabors.ImageSharp.Tests.Formats.Jpg
             {
                 TestImages.Jpeg.Progressive.Fb, TestImages.Jpeg.Progressive.Progress,
                 TestImages.Jpeg.Progressive.Festzug, TestImages.Jpeg.Progressive.Bad.BadEOF,
-                TestImages.Jpeg.Issues.ProgressiveWithTooManyCoefficients178
+                TestImages.Jpeg.Issues.BadCoeffsProgressive178
             };
 
         public const PixelTypes CommonNonDefaultPixelTypes = PixelTypes.Rgba32 | PixelTypes.Argb32 | PixelTypes.RgbaVector;
@@ -69,16 +69,7 @@ namespace SixLabors.ImageSharp.Tests.Formats.Jpg
         private static IImageDecoder OrigJpegDecoder => new OrigJpegDecoder();
 
         private static IImageDecoder PdfJsJpegDecoder => new JpegDecoder();
-
-        [Fact(Skip = "Doesn't really matter")]
-        public void ParseStream_BasicPropertiesAreCorrect1_Orig()
-        {
-            using (OrigJpegDecoderCore decoder = JpegFixture.ParseStream(TestImages.Jpeg.Progressive.Progress))
-            {
-                VerifyJpeg.VerifyComponentSizes3(decoder.Components, 43, 61, 22, 31, 22, 31);
-            }
-        }
-
+        
         [Fact]
         public void ParseStream_BasicPropertiesAreCorrect1_PdfJs()
         {
@@ -199,6 +190,11 @@ namespace SixLabors.ImageSharp.Tests.Formats.Jpg
         private void CompareJpegDecodersImpl<TPixel>(TestImageProvider<TPixel> provider, string testName)
             where TPixel : struct, IPixel<TPixel>
         {
+            if (TestEnvironment.RunsOnCI) // Debug only test
+            {
+                return;
+            }
+
             this.Output.WriteLine(provider.SourceFileOrDescription);
             provider.Utility.TestName = testName;
 

tests/ImageSharp.Tests/TestImages.cs

@@ -116,7 +116,7 @@ namespace SixLabors.ImageSharp.Tests
             {
                 public const string CriticalEOF214 = "Jpg/issues/Issue214-CriticalEOF.jpg";
                 public const string Issue159Girl = "Jpg/issues/Issue159Girl.jpg";
-                public const string ProgressiveWithTooManyCoefficients178 = "Jpg/issues/Issue178Lemon-ProgressiveWithTooManyCoefficients.jpg";
+                public const string BadCoeffsProgressive178 = "Jpg/issues/Issue178-BadCoeffsProgressive-Lemon.jpg";
             }
 
             public static readonly string[] All = Baseline.All.Concat(Progressive.All).ToArray();

tests/Images/External

@@ -1 +1 @@
-Subproject commit d91054b0e00001ea90e3098f7057c741893365c4
+Subproject commit 90cd8c2dae16b18bb99e8c2166da72b3159e58c4