Override MSBuild Copy task

copy.proj

<Project xmlns="http://schemas.microsoft.com/developer/msbuild/2003">

  <Target Name="Build">
    <Copy SourceFiles="copy.proj" DestinationFiles="destination.proj" />
  </Target>

    <UsingTask TaskName="Copy" TaskFactory="CodeTaskFactory" AssemblyFile="$(MSBuildToolsPath)\Microsoft.Build.Tasks.Core.dll">
    <ParameterGroup>
      <SourceFiles Required="true" ParameterType="Microsoft.Build.Framework.ITaskItem[]" />
      <DestinationFolder ParameterType="Microsoft.Build.Framework.ITaskItem" />
      <Retries ParameterType="System.Int32" />
      <RetryDelayMilliseconds ParameterType="System.Int32" />
      <UseHardlinksIfPossible ParameterType="System.Boolean" />
      <SkipUnchangedFiles ParameterType="System.Boolean" />
      <DestinationFiles Output="true" ParameterType="Microsoft.Build.Framework.ITaskItem[]" />
      <CopiedFiles Output="true" ParameterType="Microsoft.Build.Framework.ITaskItem[]" />
      <OverwriteReadOnlyFiles ParameterType="System.Boolean" />
    </ParameterGroup>
    <Task>
      <Reference Include="mscorlib" />
      <Reference Include="Microsoft.Build" />
      <Reference Include="Microsoft.Build.Framework" />
      <Reference Include="Microsoft.Build.Tasks.Core" />
      <Using Namespace="System" />
      <Using Namespace="System.Linq" />
      <Using Namespace="System.Text" />
      <Using Namespace="Microsoft.Build.Framework" />
      <Using Namespace="Microsoft.Build.Shared" />
      <Using Namespace="Microsoft.Build.Tasks" />
      <Using Namespace="Microsoft.Build.Utilities" />
      <Code Type="Fragment" Language="cs">
        <![CDATA[

Action<ITaskItem> DumpMetadata = i =>
{
    foreach (var m in i.MetadataNames)
    {
        Log.LogMessage(m.ToString() + "=" + i.GetMetadata(m.ToString()) + "\n");
    }
};

Func<Microsoft.Build.Tasks.Copy, string> PrintItems = c => 
{
    var sb = new StringBuilder();
    foreach(var item in c.CopiedFiles)
    {
        var originalItemSpec = item.GetMetadata("OriginalItemSpec");
        var sourceItem = c.SourceFiles.FirstOrDefault(i => 
            i.GetMetadata("OriginalItemSpec") == originalItemSpec || 
            i.ToString() == originalItemSpec || 
            i.GetMetadata("FullPath") == originalItemSpec ||
            i.GetMetadata("Identity") == originalItemSpec);
        if (sourceItem != null)
        {
            sb.AppendLine(sourceItem.GetMetadata("FullPath"));
            sb.AppendLine(item.GetMetadata("FullPath"));
        }
        else
        {
            Log.LogError(originalItemSpec);
            foreach (var s in c.SourceFiles)
            {
                DumpMetadata(s);
            }
            
            foreach (var s in c.CopiedFiles)
            {
                DumpMetadata(s);
            }
        }
    }

    return sb.ToString();
};

var copy = new Microsoft.Build.Tasks.Copy();
copy.BuildEngine = BuildEngine;
copy.SourceFiles = SourceFiles;
copy.DestinationFolder = DestinationFolder;
copy.DestinationFiles = DestinationFiles;
copy.Retries = Retries;
copy.RetryDelayMilliseconds = RetryDelayMilliseconds;
copy.UseHardlinksIfPossible = UseHardlinksIfPossible;
copy.SkipUnchangedFiles = SkipUnchangedFiles;
copy.OverwriteReadOnlyFiles = OverwriteReadOnlyFiles;
var result = copy.Execute();

//Log.LogMessage(string.Format("COPY:\r\n{0}{1}", PrintItems(copy.SourceFiles), PrintItems(copy.CopiedFiles), PrintItems(copy.DestinationFiles)));

lock(this.GetType())
{
    File.AppendAllText("copylog.txt", PrintItems(copy));
}

return result;
]]>
      </Code>
    </Task>
  </UsingTask>

</Project>

This is a sizable chunk of code and I’m interested in doing something similar. Could a license header be added?