Limit length of iptc values according to the spec

src/ImageSharp/Metadata/Profiles/IPTC/IptcProfile.cs

@@ -37,6 +37,11 @@ namespace SixLabors.ImageSharp.Metadata.Profiles.Iptc
             this.Initialize();
         }
 
+        /// <summary>
+        /// Initializes a new instance of the <see cref="IptcProfile"/> class
+        /// by making a copy from another IPTC profile.
+        /// </summary>
+        /// <param name="other">The other IPTC profile, from which the clone should be made from.</param>
         private IptcProfile(IptcProfile other)
         {
             Guard.NotNull(other, nameof(other));
@@ -85,16 +90,16 @@ namespace SixLabors.ImageSharp.Metadata.Profiles.Iptc
         /// <returns>The values found with the specified tag.</returns>
         public List<IptcValue> GetValues(IptcTag tag)
         {
-            var values = new List<IptcValue>();
+            var iptcValues = new List<IptcValue>();
             foreach (IptcValue iptcValue in this.Values)
             {
                 if (iptcValue.Tag == tag)
                 {
-                    values.Add(iptcValue);
+                    iptcValues.Add(iptcValue);
                 }
             }
 
-            return values;
+            return iptcValues;
         }
 
         /// <summary>
@@ -157,21 +162,26 @@ namespace SixLabors.ImageSharp.Metadata.Profiles.Iptc
         }
 
         /// <summary>
-        /// Sets the value of the specified tag.
+        /// Sets the value for the specified tag.
         /// </summary>
         /// <param name="tag">The tag of the iptc value.</param>
         /// <param name="encoding">The encoding to use when storing the bytes.</param>
         /// <param name="value">The value.</param>
-        public void SetValue(IptcTag tag, Encoding encoding, string value)
+        /// <param name="strict">
+        /// Indicates if length restrictions from the specification should be followed strictly.
+        /// Defaults to true.
+        /// </param>
+        public void SetValue(IptcTag tag, Encoding encoding, string value, bool strict = true)
         {
             Guard.NotNull(encoding, nameof(encoding));
 
-            if (!this.IsRepeatable(tag))
+            if (!tag.IsRepeatable())
             {
                 foreach (IptcValue iptcValue in this.Values)
                 {
                     if (iptcValue.Tag == tag)
                     {
+                        iptcValue.Strict = strict;
                         iptcValue.Encoding = encoding;
                         iptcValue.Value = value;
                         return;
@@ -179,7 +189,7 @@ namespace SixLabors.ImageSharp.Metadata.Profiles.Iptc
                 }
             }
 
-            this.values.Add(new IptcValue(tag, encoding, value));
+            this.values.Add(new IptcValue(tag, encoding, value, strict));
         }
 
         /// <summary>
@@ -187,7 +197,11 @@ namespace SixLabors.ImageSharp.Metadata.Profiles.Iptc
         /// </summary>
         /// <param name="tag">The tag of the iptc value.</param>
         /// <param name="value">The value.</param>
-        public void SetValue(IptcTag tag, string value) => this.SetValue(tag, Encoding.UTF8, value);
+        /// <param name="strict">
+        /// Indicates if length restrictions from the specification should be followed strictly.
+        /// Defaults to true.
+        /// </param>
+        public void SetValue(IptcTag tag, string value, bool strict = true) => this.SetValue(tag, Encoding.UTF8, value, strict);
 
         /// <summary>
         /// Updates the data of the profile.
@@ -251,56 +265,11 @@ namespace SixLabors.ImageSharp.Metadata.Profiles.Iptc
                 if ((count > 0) && (i + count <= this.Data.Length))
                 {
                     Buffer.BlockCopy(this.Data, i, iptcData, 0, count);
-                    this.values.Add(new IptcValue(tag, iptcData));
+                    this.values.Add(new IptcValue(tag, iptcData, false));
                 }
 
                 i += count;
             }
         }
-
-        private bool IsRepeatable(IptcTag tag)
-        {
-            switch (tag)
-            {
-                case IptcTag.RecordVersion:
-                case IptcTag.ObjectType:
-                case IptcTag.Name:
-                case IptcTag.EditStatus:
-                case IptcTag.EditorialUpdate:
-                case IptcTag.Urgency:
-                case IptcTag.Category:
-                case IptcTag.FixtureIdentifier:
-                case IptcTag.ReleaseDate:
-                case IptcTag.ReleaseTime:
-                case IptcTag.ExpirationDate:
-                case IptcTag.ExpirationTime:
-                case IptcTag.SpecialInstructions:
-                case IptcTag.ActionAdvised:
-                case IptcTag.CreatedDate:
-                case IptcTag.CreatedTime:
-                case IptcTag.DigitalCreationDate:
-                case IptcTag.DigitalCreationTime:
-                case IptcTag.OriginatingProgram:
-                case IptcTag.ProgramVersion:
-                case IptcTag.ObjectCycle:
-                case IptcTag.City:
-                case IptcTag.SubLocation:
-                case IptcTag.ProvinceState:
-                case IptcTag.CountryCode:
-                case IptcTag.Country:
-                case IptcTag.OriginalTransmissionReference:
-                case IptcTag.Headline:
-                case IptcTag.Credit:
-                case IptcTag.Source:
-                case IptcTag.CopyrightNotice:
-                case IptcTag.Caption:
-                case IptcTag.ImageType:
-                case IptcTag.ImageOrientation:
-                    return false;
-
-                default:
-                    return true;
-            }
-        }
     }
 }

src/ImageSharp/Metadata/Profiles/IPTC/IptcTag.cs

@@ -4,7 +4,7 @@
 namespace SixLabors.ImageSharp.Metadata.Profiles.Iptc
 {
     /// <summary>
-    /// All iptc tags.
+    /// All iptc tags relevant for images.
     /// </summary>
     public enum IptcTag
     {
@@ -14,222 +14,245 @@ namespace SixLabors.ImageSharp.Metadata.Profiles.Iptc
         Unknown = -1,
 
         /// <summary>
-        /// Record version, not repeatable.
+        /// Record version identifying the version of the Information Interchange Model.
+        /// Not repeatable. Max length is 2.
         /// </summary>
         RecordVersion = 0,
 
         /// <summary>
-        /// Object type, not repeatable.
+        /// Object type, not repeatable. Max Length is 67.
         /// </summary>
         ObjectType = 3,
 
         /// <summary>
-        /// Object attribute.
+        /// Object attribute. Max length is 68.
         /// </summary>
         ObjectAttribute = 4,
 
         /// <summary>
-        /// Object Name, not repeatable.
+        /// Object Name, not repeatable. Max length is 64.
         /// </summary>
         Name = 5,
 
         /// <summary>
-        /// Edit status, not repeatable.
+        /// Edit status, not repeatable. Max length is 64.
         /// </summary>
         EditStatus = 7,
 
         /// <summary>
-        /// Editorial update, not repeatable.
+        /// Editorial update, not repeatable. Max length is 2.
         /// </summary>
         EditorialUpdate = 8,
 
         /// <summary>
-        /// Urgency, not repeatable.
+        /// Urgency, not repeatable. Max length is 2.
         /// </summary>
         Urgency = 10,
 
         /// <summary>
-        /// Subject Reference.
+        /// Subject Reference. Max length is 236.
         /// </summary>
         SubjectReference = 12,
 
         /// <summary>
-        /// Category, not repeatable.
+        /// Category, not repeatable. Max length is 3.
         /// </summary>
         Category = 15,
 
         /// <summary>
-        /// Supplemental categories.
+        /// Supplemental categories. Max length is 32.
         /// </summary>
         SupplementalCategories = 20,
 
         /// <summary>
-        /// Fixture identifier, not repeatable.
+        /// Fixture identifier, not repeatable. Max length is 32.
         /// </summary>
         FixtureIdentifier = 22,
 
         /// <summary>
-        /// Keywords.
+        /// Keywords. Max length is 64.
         /// </summary>
         Keywords = 25,
 
         /// <summary>
-        /// Location code.
+        /// Location code. Max length is 3.
         /// </summary>
         LocationCode = 26,
 
         /// <summary>
-        /// Location name.
+        /// Location name. Max length is 64.
         /// </summary>
         LocationName = 27,
 
         /// <summary>
-        /// Release date, not repeatable.
+        /// Release date. Format should be CCYYMMDD,
+        /// e.g. "19890317" indicates data for release on 17 March 1989.
+        /// Not repeatable, max length is 8.
         /// </summary>
         ReleaseDate = 30,
 
         /// <summary>
-        /// Release time, not repeatable.
+        /// Release time. Format should be HHMMSS±HHMM,
+        /// e.g. "090000-0500" indicates object for use after 0900 in
+        /// New York (five hours behind UTC)
+        /// Not repeatable, max length is 11.
         /// </summary>
         ReleaseTime = 35,
 
         /// <summary>
-        /// Expiration date, not repeatable.
+        /// Expiration date. Format should be CCYYMMDD,
+        /// e.g. "19890317" indicates data for release on 17 March 1989.
+        /// Not repeatable, max length is 8.
         /// </summary>
         ExpirationDate = 37,
 
         /// <summary>
-        /// Expiration time, not repeatable.
+        /// Expiration time. Format should be HHMMSS±HHMM,
+        /// e.g. "090000-0500" indicates object for use after 0900 in
+        /// New York (five hours behind UTC)
+        /// Not repeatable, max length is 11.
         /// </summary>
         ExpirationTime = 38,
 
         /// <summary>
-        /// Special instructions, not repeatable.
+        /// Special instructions, not repeatable. Max length is 256.
         /// </summary>
         SpecialInstructions = 40,
 
         /// <summary>
-        /// Action advised, not repeatable.
+        /// Action advised, not repeatable. Max length is 2.
         /// </summary>
         ActionAdvised = 42,
 
         /// <summary>
-        /// Reference service.
+        /// Reference service. Max length is 10.
         /// </summary>
         ReferenceService = 45,
 
         /// <summary>
-        /// Reference date.
+        /// Reference date. Format should be CCYYMMDD,
+        /// e.g. "19890317" indicates data for release on 17 March 1989.
+        /// Not repeatable, max length is 8.
         /// </summary>
         ReferenceDate = 47,
 
         /// <summary>
-        /// ReferenceNumber.
+        /// ReferenceNumber. Max length is 8.
         /// </summary>
         ReferenceNumber = 50,
 
         /// <summary>
-        /// Created date, not repeatable.
+        /// Created date. Format should be CCYYMMDD,
+        /// e.g. "19890317" indicates data for release on 17 March 1989.
+        /// Not repeatable, max length is 8.
         /// </summary>
         CreatedDate = 55,
 
         /// <summary>
-        /// Created time, not repeatable.
+        /// Created time. Format should be HHMMSS±HHMM,
+        /// e.g. "090000-0500" indicates object for use after 0900 in
+        /// New York (five hours behind UTC)
+        /// Not repeatable, max length is 11.
         /// </summary>
         CreatedTime = 60,
 
         /// <summary>
-        /// Digital creation date, not repeatable.
+        /// Digital creation date. Format should be CCYYMMDD,
+        /// e.g. "19890317" indicates data for release on 17 March 1989.
+        /// Not repeatable, max length is 8.
         /// </summary>
         DigitalCreationDate = 62,
 
         /// <summary>
-        /// Digital creation time, not repeatable.
+        /// Digital creation time. Format should be HHMMSS±HHMM,
+        /// e.g. "090000-0500" indicates object for use after 0900 in
+        /// New York (five hours behind UTC)
+        /// Not repeatable, max length is 11.
         /// </summary>
         DigitalCreationTime = 63,
 
         /// <summary>
-        /// Originating program, not repeatable.
+        /// Originating program, not repeatable. Max length is 32.
         /// </summary>
         OriginatingProgram = 65,
 
         /// <summary>
-        /// Program version, not repeatable.
+        /// Program version, not repeatable. Max length is 10.
         /// </summary>
         ProgramVersion = 70,
 
         /// <summary>
-        /// Object cycle, not repeatable.
+        /// Object cycle, not repeatable. Max length is 1.
         /// </summary>
         ObjectCycle = 75,
 
         /// <summary>
-        /// Byline.
+        /// Byline. Max length is 32.
         /// </summary>
         Byline = 80,
 
         /// <summary>
-        /// Byline title.
+        /// Byline title. Max length is 32.
         /// </summary>
         BylineTitle = 85,
 
         /// <summary>
-        /// City, not repeatable.
+        /// City, not repeatable. Max length is 32.
         /// </summary>
         City = 90,
 
         /// <summary>
-        /// Sub location, not repeatable.
+        /// Sub location, not repeatable. Max length is 32.
         /// </summary>
         SubLocation = 92,
 
         /// <summary>
-        /// Province/State, not repeatable.
+        /// Province/State, not repeatable. Max length is 32.
         /// </summary>
         ProvinceState = 95,
 
         /// <summary>
-        /// Country code, not repeatable.
+        /// Country code, not repeatable. Max length is 3.
         /// </summary>
         CountryCode = 100,
 
         /// <summary>
-        /// Country, not repeatable.
+        /// Country, not repeatable. Max length is 64.
         /// </summary>
         Country = 101,
 
         /// <summary>
-        /// Original transmission reference, not repeatable.
+        /// Original transmission reference, not repeatable. Max length is 32.
         /// </summary>
         OriginalTransmissionReference = 103,
 
         /// <summary>
-        /// Headline, not repeatable.
+        /// Headline, not repeatable. Max length is 256.
         /// </summary>
         Headline = 105,
 
         /// <summary>
-        /// Credit, not repeatable.
+        /// Credit, not repeatable. Max length is 32.
         /// </summary>
         Credit = 110,
 
         /// <summary>
-        /// Source, not repeatable.
+        /// Source, not repeatable. Max length is 32.
         /// </summary>
         Source = 115,
 
         /// <summary>
-        /// Copyright notice, not repeatable.
+        /// Copyright notice, not repeatable. Max length is 128.
         /// </summary>
         CopyrightNotice = 116,
 
         /// <summary>
-        /// Contact.
+        /// Contact. Max length 128.
         /// </summary>
         Contact = 118,
 
         /// <summary>
-        /// Caption, not repeatable.
+        /// Caption, not repeatable. Max length is 2000.
         /// </summary>
         Caption = 120,
 
@@ -239,17 +262,17 @@ namespace SixLabors.ImageSharp.Metadata.Profiles.Iptc
         LocalCaption = 121,
 
         /// <summary>
-        /// Caption writer.
+        /// Caption writer. Max length is 32.
         /// </summary>
         CaptionWriter = 122,
 
         /// <summary>
-        /// Image type, not repeatable.
+        /// Image type, not repeatable. Max length is 2.
         /// </summary>
         ImageType = 130,
 
         /// <summary>
-        /// Image orientation, not repeatable.
+        /// Image orientation, not repeatable. Max length is 1.
         /// </summary>
         ImageOrientation = 131,
 

src/ImageSharp/Metadata/Profiles/IPTC/IptcTagExtensions.cs

@@ -0,0 +1,121 @@
+// Copyright (c) Six Labors and contributors.
+// Licensed under the Apache License, Version 2.0.
+
+namespace SixLabors.ImageSharp.Metadata.Profiles.Iptc
+{
+    /// <summary>
+    /// Extension methods for IPTC tags.
+    /// </summary>
+    public static class IptcTagExtensions
+    {
+        /// <summary>
+        /// Maximum length of the IPTC value with the given tag according to the specification.
+        /// </summary>
+        /// <param name="tag">The tag to check the max length for.</param>
+        /// <returns>The maximum length.</returns>
+        public static int MaxLength(this IptcTag tag)
+        {
+            return tag switch
+            {
+                IptcTag.RecordVersion => 2,
+                IptcTag.ObjectType => 67,
+                IptcTag.ObjectAttribute => 68,
+                IptcTag.Name => 64,
+                IptcTag.EditStatus => 64,
+                IptcTag.EditorialUpdate => 2,
+                IptcTag.Urgency => 1,
+                IptcTag.SubjectReference => 236,
+                IptcTag.Category => 3,
+                IptcTag.SupplementalCategories => 32,
+                IptcTag.FixtureIdentifier => 32,
+                IptcTag.Keywords => 64,
+                IptcTag.LocationCode => 3,
+                IptcTag.LocationName => 64,
+                IptcTag.ReleaseDate => 8,
+                IptcTag.ReleaseTime => 11,
+                IptcTag.ExpirationDate => 8,
+                IptcTag.ExpirationTime => 11,
+                IptcTag.SpecialInstructions => 256,
+                IptcTag.ActionAdvised => 2,
+                IptcTag.ReferenceService => 10,
+                IptcTag.ReferenceDate => 8,
+                IptcTag.ReferenceNumber => 8,
+                IptcTag.CreatedDate => 8,
+                IptcTag.CreatedTime => 11,
+                IptcTag.DigitalCreationDate => 8,
+                IptcTag.DigitalCreationTime => 11,
+                IptcTag.OriginatingProgram => 32,
+                IptcTag.ProgramVersion => 10,
+                IptcTag.ObjectCycle => 1,
+                IptcTag.Byline => 32,
+                IptcTag.BylineTitle => 32,
+                IptcTag.City => 32,
+                IptcTag.SubLocation => 32,
+                IptcTag.ProvinceState => 32,
+                IptcTag.CountryCode => 3,
+                IptcTag.Country => 64,
+                IptcTag.OriginalTransmissionReference => 32,
+                IptcTag.Headline => 256,
+                IptcTag.Credit => 32,
+                IptcTag.Source => 32,
+                IptcTag.CopyrightNotice => 128,
+                IptcTag.Contact => 128,
+                IptcTag.Caption => 2000,
+                IptcTag.CaptionWriter => 32,
+                IptcTag.ImageType => 2,
+                IptcTag.ImageOrientation => 1,
+                _ => 256
+            };
+        }
+
+        /// <summary>
+        /// Determines if the given tag can be repeated according to the specification.
+        /// </summary>
+        /// <param name="tag">The tag to check.</param>
+        /// <returns>True, if the tag can occur multiple times.</returns>
+        public static bool IsRepeatable(this IptcTag tag)
+        {
+            switch (tag)
+            {
+                case IptcTag.RecordVersion:
+                case IptcTag.ObjectType:
+                case IptcTag.Name:
+                case IptcTag.EditStatus:
+                case IptcTag.EditorialUpdate:
+                case IptcTag.Urgency:
+                case IptcTag.Category:
+                case IptcTag.FixtureIdentifier:
+                case IptcTag.ReleaseDate:
+                case IptcTag.ReleaseTime:
+                case IptcTag.ExpirationDate:
+                case IptcTag.ExpirationTime:
+                case IptcTag.SpecialInstructions:
+                case IptcTag.ActionAdvised:
+                case IptcTag.CreatedDate:
+                case IptcTag.CreatedTime:
+                case IptcTag.DigitalCreationDate:
+                case IptcTag.DigitalCreationTime:
+                case IptcTag.OriginatingProgram:
+                case IptcTag.ProgramVersion:
+                case IptcTag.ObjectCycle:
+                case IptcTag.City:
+                case IptcTag.SubLocation:
+                case IptcTag.ProvinceState:
+                case IptcTag.CountryCode:
+                case IptcTag.Country:
+                case IptcTag.OriginalTransmissionReference:
+                case IptcTag.Headline:
+                case IptcTag.Credit:
+                case IptcTag.Source:
+                case IptcTag.CopyrightNotice:
+                case IptcTag.Caption:
+                case IptcTag.ImageType:
+                case IptcTag.ImageOrientation:
+                    return false;
+
+                default:
+                    return true;
+            }
+        }
+    }
+}

src/ImageSharp/Metadata/Profiles/IPTC/IptcValue.cs

@@ -28,24 +28,35 @@ namespace SixLabors.ImageSharp.Metadata.Profiles.Iptc
             }
 
             this.Tag = other.Tag;
+            this.Strict = other.Strict;
         }
 
-        internal IptcValue(IptcTag tag, byte[] value)
+        internal IptcValue(IptcTag tag, byte[] value, bool strict)
         {
             Guard.NotNull(value, nameof(value));
 
+            this.Strict = strict;
             this.Tag = tag;
             this.data = value;
             this.encoding = Encoding.UTF8;
         }
 
-        internal IptcValue(IptcTag tag, Encoding encoding, string value)
+        internal IptcValue(IptcTag tag, Encoding encoding, string value, bool strict)
         {
+            this.Strict = strict;
             this.Tag = tag;
             this.encoding = encoding;
             this.Value = value;
         }
 
+        internal IptcValue(IptcTag tag, string value, bool strict)
+        {
+            this.Strict = strict;
+            this.Tag = tag;
+            this.encoding = Encoding.UTF8;
+            this.Value = value;
+        }
+
         /// <summary>
         /// Gets or sets the encoding to use for the Value.
         /// </summary>
@@ -66,6 +77,12 @@ namespace SixLabors.ImageSharp.Metadata.Profiles.Iptc
         /// </summary>
         public IptcTag Tag { get; }
 
+        /// <summary>
+        /// Gets or sets a value indicating whether to be enforce value length restrictions according
+        /// to the specification.
+        /// </summary>
+        public bool Strict { get; set; }
+
         /// <summary>
         /// Gets or sets the value.
         /// </summary>
@@ -76,11 +93,23 @@ namespace SixLabors.ImageSharp.Metadata.Profiles.Iptc
             {
                 if (string.IsNullOrEmpty(value))
                 {
-                    this.data = new byte[0];
+                    this.data = Array.Empty<byte>();
                 }
                 else
                 {
-                    this.data = this.encoding.GetBytes(value);
+                    int maxLength = this.Tag.MaxLength();
+                    byte[] valueBytes;
+                    if (this.Strict && value.Length > maxLength)
+                    {
+                        var cappedValue = value.Substring(0, maxLength);
+                        valueBytes = this.encoding.GetBytes(cappedValue);
+                    }
+                    else
+                    {
+                        valueBytes = this.encoding.GetBytes(value);
+                    }
+
+                    this.data = valueBytes;
                 }
             }
         }

src/ImageSharp/Metadata/Profiles/IPTC/README.md

@@ -1,9 +1,11 @@
 IPTC source code is from [Magick.NET](https://github.com/dlemstra/Magick.NET)
 
-Information about IPTC can be found here in the folowing sources:
+Information about IPTC can be found here in the following sources:
 
 - [metacpan.org, APP13-segment](https://metacpan.org/pod/Image::MetaData::JPEG::Structures#Structure-of-a-Photoshop-style-APP13-segment)
 
 - [iptc.org](https://www.iptc.org/std/photometadata/documentation/userguide/)
 
-- [Adobe File Formats Specification](http://oldschoolprg.x10.mx/downloads/ps6ffspecsv2.pdf)
+- [Adobe File Formats Specification](http://oldschoolprg.x10.mx/downloads/ps6ffspecsv2.pdf)
+
+- [Tag Overview](https://exiftool.org/TagNames/IPTC.html)

tests/ImageSharp.Tests/Metadata/Profiles/IPTC/IptcProfileTests.cs

@@ -1,6 +1,7 @@
 // Copyright (c) Six Labors and contributors.
 // Licensed under the Apache License, Version 2.0.
 
+using System;
 using System.Collections.Generic;
 using System.IO;
 using System.Linq;
@@ -15,6 +16,31 @@ namespace SixLabors.ImageSharp.Tests.Metadata.Profiles.IPTC
     {
         private static JpegDecoder JpegDecoder => new JpegDecoder() { IgnoreMetadata = false };
 
+        public static IEnumerable<object[]> allIptcTags()
+        {
+            foreach (object tag in Enum.GetValues(typeof(IptcTag)))
+            {
+                yield return new object[] { tag };
+            }
+        }
+
+        [Theory]
+        [MemberData("allIptcTags")]
+        public void IptcProfile_SetValue_WithStrictOption_Works(IptcTag tag)
+        {
+            // arrange
+            var profile = new IptcProfile();
+            var value = new string('s', tag.MaxLength() + 1);
+            var expectedLength = tag.MaxLength();
+
+            // act
+            profile.SetValue(tag, value);
+
+            // assert
+            IptcValue actual = profile.GetValues(tag).First();
+            Assert.Equal(expectedLength, actual.Value.Length);
+        }
+
         [Theory]
         [WithFile(TestImages.Jpeg.Baseline.Iptc, PixelTypes.Rgba32)]
         public void ReadIptcMetadata_Works<TPixel>(TestImageProvider<TPixel> provider)
@@ -91,16 +117,17 @@ namespace SixLabors.ImageSharp.Tests.Metadata.Profiles.IPTC
 
             // assert
             Assert.Equal(2, clone.Values.Count());
-            ContainsIptcValue(clone.Values, IptcTag.CaptionWriter, captionWriter);
-            ContainsIptcValue(clone.Values, IptcTag.Caption, "changed");
-            ContainsIptcValue(profile.Values, IptcTag.Caption, caption);
+            var cloneValues = clone.Values.ToList();
+            ContainsIptcValue(cloneValues, IptcTag.CaptionWriter, captionWriter);
+            ContainsIptcValue(cloneValues, IptcTag.Caption, "changed");
+            ContainsIptcValue(profile.Values.ToList(), IptcTag.Caption, caption);
         }
 
         [Fact]
         public void IptcValue_CloneIsDeep()
         {
             // arrange
-            var iptcValue = new IptcValue(IptcTag.Caption, System.Text.Encoding.UTF8, "test");
+            var iptcValue = new IptcValue(IptcTag.Caption, System.Text.Encoding.UTF8, "test", true);
 
             // act
             IptcValue clone = iptcValue.DeepClone();
@@ -132,6 +159,13 @@ namespace SixLabors.ImageSharp.Tests.Metadata.Profiles.IPTC
             ContainsIptcValue(iptcValues, IptcTag.Caption, expectedCaption);
         }
 
+        [Fact]
+        public void IptcProfile_SetNewValue_RespectsMaxLength()
+        {
+            // arrange
+            var profile = new IptcProfile();
+        }
+
         [Theory]
         [InlineData(IptcTag.ObjectAttribute)]
         [InlineData(IptcTag.SubjectReference)]
@@ -153,10 +187,10 @@ namespace SixLabors.ImageSharp.Tests.Metadata.Profiles.IPTC
             var profile = new IptcProfile();
             var expectedValue1 = "test";
             var expectedValue2 = "another one";
-            profile.SetValue(tag, expectedValue1);
+            profile.SetValue(tag, expectedValue1, false);
 
             // act
-            profile.SetValue(tag, expectedValue2);
+            profile.SetValue(tag, expectedValue2, false);
 
             // assert
             var values = profile.Values.ToList();
@@ -204,10 +238,10 @@ namespace SixLabors.ImageSharp.Tests.Metadata.Profiles.IPTC
             // arrange
             var profile = new IptcProfile();
             var expectedValue = "another one";
-            profile.SetValue(tag, "test");
+            profile.SetValue(tag, "test", false);
 
             // act
-            profile.SetValue(tag, expectedValue);
+            profile.SetValue(tag, expectedValue, false);
 
             // assert
             var values = profile.Values.ToList();
@@ -244,7 +278,7 @@ namespace SixLabors.ImageSharp.Tests.Metadata.Profiles.IPTC
 
             // assert
             Assert.True(result, "removed result should be true");
-            ContainsIptcValue(profile.Values, IptcTag.Byline, "test");
+            ContainsIptcValue(profile.Values.ToList(), IptcTag.Byline, "test");
         }
 
         [Fact]
@@ -264,10 +298,10 @@ namespace SixLabors.ImageSharp.Tests.Metadata.Profiles.IPTC
             Assert.Equal(2, result.Count);
         }
 
-        private static void ContainsIptcValue(IEnumerable<IptcValue> values, IptcTag tag, string value)
+        private static void ContainsIptcValue(List<IptcValue> values, IptcTag tag, string value)
         {
             Assert.True(values.Any(val => val.Tag == tag), $"Missing iptc tag {tag}");
-            Assert.True(values.Contains(new IptcValue(tag, System.Text.Encoding.UTF8.GetBytes(value))), $"expected iptc value '{value}' was not found for tag '{tag}'");
+            Assert.True(values.Contains(new IptcValue(tag, System.Text.Encoding.UTF8.GetBytes(value), false)), $"expected iptc value '{value}' was not found for tag '{tag}'");
         }
 
         private static Image<Rgba32> WriteAndReadJpeg(Image<Rgba32> image)