Merge pull request #2505 from sonbua/backport/2243

V2 backport: 2243 - Ignore unknown chunks for WEBP

Author: JimBobSquarePants

src/ImageSharp/Formats/Webp/WebpDecoderCore.cs

@@ -277,7 +277,9 @@ private WebpImageInfo ReadVp8XHeader()
                 }
                 else
                 {
-                    WebpThrowHelper.ThrowImageFormatException("Unexpected chunk followed VP8X header");
+                    // Ignore unknown chunks.
+                    uint chunkSize = this.ReadChunkSize();
+                    this.currentStream.Skip((int)chunkSize);
                 }
             }
 

tests/ImageSharp.Tests/Formats/WebP/WebpDecoderTests.cs

@@ -358,6 +358,17 @@ public void WebpDecoder_CanDecode_Issue1594<TPixel>(TestImageProvider<TPixel> pr
             }
         }
 
+        // https://github.com/SixLabors/ImageSharp/issues/2243
+        [Theory]
+        [WithFile(Lossy.Issue2243, PixelTypes.Rgba32)]
+        public void WebpDecoder_CanDecode_Issue2243<TPixel>(TestImageProvider<TPixel> provider)
+            where TPixel : unmanaged, IPixel<TPixel>
+        {
+            using Image<TPixel> image = provider.GetImage(WebpDecoder);
+            image.DebugSave(provider);
+            image.CompareToOriginal(provider, ReferenceDecoder);
+        }
+
         [Theory]
         [WithFile(Lossless.LossLessCorruptImage3, PixelTypes.Rgba32)]
         public void WebpDecoder_ThrowImageFormatException_OnInvalidImages<TPixel>(TestImageProvider<TPixel> provider)

tests/ImageSharp.Tests/TestImages.cs

@@ -741,6 +741,7 @@ public static class Lossy
 
                 // Issues
                 public const string Issue1594 = "Webp/issues/Issue1594.webp";
+                public const string Issue2243 = "Webp/issues/Issue2243.webp";
             }
         }