Only throw for multi SOF when fully decoding.

JimBobSquarePants · JimBobSquarePants · commit 2bf18d9c00eb · 2020-06-11T23:48:36.000+01:00
diff --git a/src/ImageSharp/Formats/Jpeg/JpegDecoderCore.cs b/src/ImageSharp/Formats/Jpeg/JpegDecoderCore.cs
@@ -812,6 +812,11 @@ private void ProcessStartOfFrameMarker(int remaining, in JpegFileMarker frameMar
         {
             if (this.Frame != null)
             {
+                if (metadataOnly)
+                {
+                    return;
+                }
+
                 JpegThrowHelper.ThrowInvalidImageContentException("Multiple SOF markers. Only single frame jpegs supported.");
             }
 
diff --git a/tests/ImageSharp.Tests/Formats/Jpg/JpegDecoderTests.Images.cs b/tests/ImageSharp.Tests/Formats/Jpg/JpegDecoderTests.Images.cs
@@ -32,6 +32,7 @@ public partial class JpegDecoderTests
                 TestImages.Jpeg.Issues.ExifGetString750Load,
                 TestImages.Jpeg.Issues.ExifGetString750Transform,
                 TestImages.Jpeg.Issues.BadSubSampling1076,
+                TestImages.Jpeg.Issues.IdentifyMultiFrame1211,
 
                 // LibJpeg can open this despite the invalid density units.
                 TestImages.Jpeg.Issues.Fuzz.ArgumentOutOfRangeException825B,
diff --git a/tests/ImageSharp.Tests/Formats/Jpg/JpegDecoderTests.Metadata.cs b/tests/ImageSharp.Tests/Formats/Jpg/JpegDecoderTests.Metadata.cs
@@ -38,6 +38,7 @@ public partial class JpegDecoderTests
             { true, TestImages.Jpeg.Baseline.Jpeg400, 8, false, false },
             { true, TestImages.Jpeg.Baseline.Snake, 24, true, true },
             { true, TestImages.Jpeg.Baseline.Jpeg420Exif, 24, true, false },
+            { true, TestImages.Jpeg.Issues.IdentifyMultiFrame1211, 24, true, true },
         };
 
         public static readonly TheoryData<string, int, int, PixelResolutionUnit> RatioFiles =
diff --git a/tests/ImageSharp.Tests/TestImages.cs b/tests/ImageSharp.Tests/TestImages.cs
@@ -229,6 +229,7 @@ public static class Issues
                 public const string IncorrectResize1006 = "Jpg/issues/issue1006-incorrect-resize.jpg";
                 public const string ExifResize1049 = "Jpg/issues/issue1049-exif-resize.jpg";
                 public const string BadSubSampling1076 = "Jpg/issues/issue-1076-invalid-subsampling.jpg";
+                public const string IdentifyMultiFrame1211 = "Jpg/issues/issue-1221-identify-multi-frame.jpg";
 
                 public static class Fuzz
                 {
diff --git a/tests/Images/Input/Jpg/issues/issue-1221-identify-multi-frame.jpg b/tests/Images/Input/Jpg/issues/issue-1221-identify-multi-frame.jpg

Original file line number	Diff line number	Diff line change
`@@ -812,6 +812,11 @@ private void ProcessStartOfFrameMarker(int remaining, in JpegFileMarker frameMar`
`812`	`812`	`{`
`813`	`813`	`if (this.Frame != null)`
`814`	`814`	`{`
	`815`	`+ if (metadataOnly)`
	`816`	`+ {`
	`817`	`+ return;`
	`818`	`+ }`
	`819`	`+`
`815`	`820`	`JpegThrowHelper.ThrowInvalidImageContentException("Multiple SOF markers. Only single frame jpegs supported.");`
`816`	`821`	`}`
`817`	`822`
Original file line number	Diff line number	Diff line change
`@@ -229,6 +229,7 @@ public static class Issues`
`229`	`229`	`public const string IncorrectResize1006 = "Jpg/issues/issue1006-incorrect-resize.jpg";`
`230`	`230`	`public const string ExifResize1049 = "Jpg/issues/issue1049-exif-resize.jpg";`
`231`	`231`	`public const string BadSubSampling1076 = "Jpg/issues/issue-1076-invalid-subsampling.jpg";`
	`232`	`+ public const string IdentifyMultiFrame1211 = "Jpg/issues/issue-1221-identify-multi-frame.jpg";`
`232`	`233`
`233`	`234`	`public static class Fuzz`
`234`	`235`	`{`