From 66e08f972be750ea1dc7ff99cb25bb81ee62589b Mon Sep 17 00:00:00 2001
From: Dirk Lemstra <dirk@git.imagemagick.org>
Date: Thu, 6 Jul 2017 20:52:11 +0200
Subject: [PATCH] Also support non ushort values of ExifTag.Orientation (Fixes
 #271).

---
 .../Processing/Transforms/AutoOrient.cs       | 12 ++++++-
 .../Processing/Transforms/AutoOrientTests.cs  | 35 +++++++++++++++++++
 2 files changed, 46 insertions(+), 1 deletion(-)

diff --git a/src/ImageSharp/Processing/Transforms/AutoOrient.cs b/src/ImageSharp/Processing/Transforms/AutoOrient.cs
index 07e5d5bc9..7e7c66460 100644
--- a/src/ImageSharp/Processing/Transforms/AutoOrient.cs
+++ b/src/ImageSharp/Processing/Transforms/AutoOrient.cs
@@ -5,6 +5,7 @@
 
 namespace ImageSharp
 {
+    using System;
     using ImageSharp.PixelFormats;
 
     using ImageSharp.Processing;
@@ -77,7 +78,16 @@ namespace ImageSharp
                 return Orientation.Unknown;
             }
 
-            var orientation = (Orientation)value.Value;
+            Orientation orientation;
+            if (value.DataType == ExifDataType.Short)
+            {
+                orientation = (Orientation)value.Value;
+            }
+            else
+            {
+                orientation = (Orientation)Convert.ToUInt16(value.Value);
+                source.MetaData.ExifProfile.RemoveValue(ExifTag.Orientation);
+            }
 
             source.MetaData.ExifProfile.SetValue(ExifTag.Orientation, (ushort)Orientation.TopLeft);
 
diff --git a/tests/ImageSharp.Tests/Processing/Transforms/AutoOrientTests.cs b/tests/ImageSharp.Tests/Processing/Transforms/AutoOrientTests.cs
index 7bc0c8bb5..0646dc937 100644
--- a/tests/ImageSharp.Tests/Processing/Transforms/AutoOrientTests.cs
+++ b/tests/ImageSharp.Tests/Processing/Transforms/AutoOrientTests.cs
@@ -5,6 +5,7 @@
 
 namespace ImageSharp.Tests.Processing.Transforms
 {
+    using System;
     using ImageSharp.PixelFormats;
     using ImageSharp.Processing;
 
@@ -28,6 +29,16 @@ namespace ImageSharp.Tests.Processing.Transforms
             { RotateType.Rotate90,  FlipType.None,       8 },
         };
 
+        public static readonly TheoryData<ExifDataType, byte[]> InvalidOrientationValues
+            = new TheoryData<ExifDataType, byte[]>
+        {
+            { ExifDataType.Byte, new byte[] { 1 } },
+            { ExifDataType.SignedByte, new byte[] { 2 } },
+            { ExifDataType.SignedShort, BitConverter.GetBytes((short) 3) },
+            { ExifDataType.Long, BitConverter.GetBytes((uint) 4) },
+            { ExifDataType.SignedLong, BitConverter.GetBytes((int) 5) }
+        };
+
         [Theory]
         [WithFileCollection(nameof(FlipFiles), nameof(OrientationValues), DefaultPixelType)]
         public void ImageShouldAutoRotate<TPixel>(TestImageProvider<TPixel> provider, RotateType rotateType, FlipType flipType, ushort orientation)
@@ -44,5 +55,29 @@ namespace ImageSharp.Tests.Processing.Transforms
                     .DebugSave(provider, string.Join("_", rotateType, flipType, orientation, "2_after"), Extensions.Bmp);
             }
         }
+
+        [Theory]
+        [WithFileCollection(nameof(FlipFiles), nameof(InvalidOrientationValues), DefaultPixelType)]
+        public void ImageShouldAutoRotateInvalidValues<TPixel>(TestImageProvider<TPixel> provider, ExifDataType dataType, byte[] orientation)
+            where TPixel : struct, IPixel<TPixel>
+        {
+            var profile = new ExifProfile();
+            profile.SetValue(ExifTag.JPEGTables, orientation);
+
+            byte[] bytes = profile.ToByteArray();
+            // Change the tag into ExifTag.Orientation
+            bytes[16] = 18;
+            bytes[17] = 1;
+            // Change the data type
+            bytes[18] = (byte)dataType;
+            // Change the number of components
+            bytes[20] = 1;
+
+            using (Image<TPixel> image = provider.GetImage())
+            {
+                image.MetaData.ExifProfile = new ExifProfile(bytes);
+                image.AutoOrient();
+            }
+        }
     }
 }
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