Added unit test.

tests/ImageSharp.Tests/MetaData/Profiles/Exif/ExifProfileTests.cs

@@ -292,6 +292,22 @@ namespace SixLabors.ImageSharp.Tests
             }
         }
 
+        [Fact]
+        public void TestArrayValueWithUnspecifiedSize()
+        {
+            // This images contains array in the exif profile that has zero components.
+            Image<Rgba32> image = TestFile.Create(TestImages.Jpeg.Issues.InvalidCast520).CreateImage();
+
+            ExifProfile profile = image.MetaData.ExifProfile;
+            Assert.NotNull(profile);
+
+            // Force parsing of the profile.
+            Assert.Equal(24, profile.Values.Count);
+
+            byte[] bytes = profile.ToByteArray();
+            Assert.Equal(495, bytes.Length);
+        }
+
         private static ExifProfile GetExifProfile()
         {
             Image<Rgba32> image = TestFile.Create(TestImages.Jpeg.Baseline.Floorplan).CreateImage();

tests/ImageSharp.Tests/TestImages.cs

@@ -136,6 +136,7 @@ namespace SixLabors.ImageSharp.Tests
                 public const string MultiHuffmanBaseline394 = "Jpg/issues/Issue394-MultiHuffmanBaseline-Speakers.jpg";
                 public const string NoEoiProgressive517 = "Jpg/issues/Issue517-No-EOI-Progressive.jpg";
                 public const string BadRstProgressive518 = "Jpg/issues/Issue518-Bad-RST-Progressive.jpg";
+                public const string InvalidCast520 = "Jpg/issues/Issue520-InvalidCast.jpg";
             }
 
             public static readonly string[] All = Baseline.All.Concat(Progressive.All).ToArray();

tests/Images/Input/Jpg/issues/Issue520-InvalidCast.jpg

@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:3fe23e56bf22a220efdc75cb98e7c9a7a5e29ca960be5e5dc5ca3a0a33d8cd2c
+size 7751