SixLabors · JimBobSquarePants · Mar 19, 2024 · Mar 18, 2024 · Mar 18, 2024 · Mar 18, 2024
diff --git a/src/ImageSharp/Formats/Jpeg/Components/Decoder/JpegBitReader.cs b/src/ImageSharp/Formats/Jpeg/Components/Decoder/JpegBitReader.cs
@@ -22,6 +22,9 @@ internal struct JpegBitReader
    // Whether there is no more good data to pull from the stream for the current mcu.
    private bool badData;

+    // How many times have we hit the eof.
+    private int eofHitCount;
+
    public JpegBitReader(BufferedReadStream stream)
    {
        this.stream = stream;
@@ -31,6 +34,7 @@ public JpegBitReader(BufferedReadStream stream)
        this.MarkerPosition = 0;
        this.badData = false;
        this.NoData = false;
+        this.eofHitCount = 0;
    }

    /// <summary>
@@ -219,11 +223,16 @@ private int ReadStream()
        // we know we have hit the EOI and completed decoding the scan buffer.
        if (value == -1 || (this.badData && this.data == 0 && this.stream.Position >= this.stream.Length))
        {
-            // We've encountered the end of the file stream which means there's no EOI marker
+            // We've hit the end of the file stream more times than allowed which means there's no EOI marker
            // in the image or the SOS marker has the wrong dimensions set.
-            this.badData = true;
-            this.NoData = true;
-            value = 0;
+            if (this.eofHitCount > JpegConstants.Huffman.FetchLoop)
+            {
+                this.badData = true;
+                this.NoData = true;
+                value = 0;
+            }
+
+            this.eofHitCount++;
        }

        return value;

diff --git a/tests/ImageSharp.Tests/Formats/Jpg/JpegDecoderTests.cs b/tests/ImageSharp.Tests/Formats/Jpg/JpegDecoderTests.cs
@@ -364,4 +364,15 @@ public void Issue2517_DecodeWorks<TPixel>(TestImageProvider<TPixel> provider)
        image.DebugSave(provider);
        image.CompareToOriginal(provider);
    }
+
+    // https://github.com/SixLabors/ImageSharp/issues/2638
+    [Theory]
+    [WithFile(TestImages.Jpeg.Issues.Issue2638, PixelTypes.Rgba32)]
+    public void Issue2638_DecodeWorks<TPixel>(TestImageProvider<TPixel> provider)
+        where TPixel : unmanaged, IPixel<TPixel>
+    {
+        using Image<TPixel> image = provider.GetImage(JpegDecoder.Instance);
+        image.DebugSave(provider);
+        image.CompareToOriginal(provider);
+    }
 }
diff --git a/tests/ImageSharp.Tests/TestImages.cs b/tests/ImageSharp.Tests/TestImages.cs
@@ -315,6 +315,7 @@ public static class Issues
            public const string Issue2564 = "Jpg/issues/issue-2564.jpg";
            public const string HangBadScan = "Jpg/issues/Hang_C438A851.jpg";
            public const string Issue2517 = "Jpg/issues/issue2517-bad-d7.jpg";
+            public const string Issue2638 = "Jpg/issues/Issue2638.jpg";

            public static class Fuzz
            {

diff --git a/tests/Images/Input/Jpg/issues/Issue2638.jpg b/tests/Images/Input/Jpg/issues/Issue2638.jpg