From 03547d078c5d47a4bcc8185a869daf1237baeab0 Mon Sep 17 00:00:00 2001
From: Brian Popow <popow@gmx.de>
Date: Sun, 26 Apr 2020 17:32:22 +0200
Subject: [PATCH] Identify reads now exif data

---
 src/ImageSharp/Formats/Png/PngDecoderCore.cs  |   9 +++
 .../Formats/Png/PngMetadataTests.cs           |  58 ++++++++++++++++++
 tests/Images/Input/Png/PngWithMetaData.png    | Bin 805 -> 751 bytes
 3 files changed, 67 insertions(+)

diff --git a/src/ImageSharp/Formats/Png/PngDecoderCore.cs b/src/ImageSharp/Formats/Png/PngDecoderCore.cs
index 7d9011a55..a5bcff3b2 100644
--- a/src/ImageSharp/Formats/Png/PngDecoderCore.cs
+++ b/src/ImageSharp/Formats/Png/PngDecoderCore.cs
@@ -278,6 +278,15 @@ namespace SixLabors.ImageSharp.Formats.Png
                                 break;
                             case PngChunkType.InternationalText:
                                 this.ReadInternationalTextChunk(pngMetadata, chunk.Data.Array.AsSpan(0, chunk.Length));
+                                break;
+                            case PngChunkType.Exif:
+                                if (!this.ignoreMetadata)
+                                {
+                                    var exifData = new byte[chunk.Length];
+                                    Buffer.BlockCopy(chunk.Data.Array, 0, exifData, 0, chunk.Length);
+                                    metadata.ExifProfile = new ExifProfile(exifData);
+                                }
+
                                 break;
                             case PngChunkType.End:
                                 this.isEndChunkReached = true;
diff --git a/tests/ImageSharp.Tests/Formats/Png/PngMetadataTests.cs b/tests/ImageSharp.Tests/Formats/Png/PngMetadataTests.cs
index ee4e4f3c2..bf4206600 100644
--- a/tests/ImageSharp.Tests/Formats/Png/PngMetadataTests.cs
+++ b/tests/ImageSharp.Tests/Formats/Png/PngMetadataTests.cs
@@ -6,6 +6,7 @@ using System.IO;
 using System.Linq;
 using SixLabors.ImageSharp.Formats.Png;
 using SixLabors.ImageSharp.Metadata;
+using SixLabors.ImageSharp.Metadata.Profiles.Exif;
 using SixLabors.ImageSharp.PixelFormats;
 using Xunit;
 
@@ -129,6 +130,40 @@ namespace SixLabors.ImageSharp.Tests.Formats.Png
             }
         }
 
+        [Theory]
+        [WithFile(TestImages.Png.PngWithMetadata, PixelTypes.Rgba32)]
+        public void Decode_ReadsExifData<TPixel>(TestImageProvider<TPixel> provider)
+            where TPixel : unmanaged, IPixel<TPixel>
+        {
+            var decoder = new PngDecoder
+            {
+                IgnoreMetadata = false
+            };
+
+            using (Image<TPixel> image = provider.GetImage(decoder))
+            {
+                Assert.NotNull(image.Metadata.ExifProfile);
+                ExifProfile exif = image.Metadata.ExifProfile;
+                VerifyExifDataIsPresent(exif);
+            }
+        }
+
+        [Theory]
+        [WithFile(TestImages.Png.PngWithMetadata, PixelTypes.Rgba32)]
+        public void Decode_IgnoresExifData_WhenIgnoreMetadataIsTrue<TPixel>(TestImageProvider<TPixel> provider)
+            where TPixel : unmanaged, IPixel<TPixel>
+        {
+            var decoder = new PngDecoder
+            {
+                IgnoreMetadata = true
+            };
+
+            using (Image<TPixel> image = provider.GetImage(decoder))
+            {
+                Assert.Null(image.Metadata.ExifProfile);
+            }
+        }
+
         [Fact]
         public void Decode_IgnoreMetadataIsFalse_TextChunkIsRead()
         {
@@ -215,6 +250,29 @@ namespace SixLabors.ImageSharp.Tests.Formats.Png
             }
         }
 
+        [Theory]
+        [InlineData(TestImages.Png.PngWithMetadata)]
+        public void Identify_ReadsExifData(string imagePath)
+        {
+            var testFile = TestFile.Create(imagePath);
+            using (var stream = new MemoryStream(testFile.Bytes, false))
+            {
+                IImageInfo imageInfo = Image.Identify(stream);
+                Assert.NotNull(imageInfo);
+                Assert.NotNull(imageInfo.Metadata.ExifProfile);
+                ExifProfile exif = imageInfo.Metadata.ExifProfile;
+                VerifyExifDataIsPresent(exif);
+            }
+        }
+
+        private static void VerifyExifDataIsPresent(ExifProfile exif)
+        {
+            Assert.Equal(1, exif.Values.Count);
+            IExifValue<string> software = exif.GetValue(ExifTag.Software);
+            Assert.NotNull(software);
+            Assert.Equal("ImageSharp", software.Value);
+        }
+
         private static void VerifyTextDataIsPresent(PngMetadata meta)
         {
             Assert.NotNull(meta);
diff --git a/tests/Images/Input/Png/PngWithMetaData.png b/tests/Images/Input/Png/PngWithMetaData.png
index af417b1f307329d72b536ab69170c1a06399d745..b5d0d344d7cf111b4f5d1784fac9b4fb1439b61a 100644
GIT binary patch
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