COM Wrappers are not copied correctly to publish directory when there is more than one COM reference

Repro

With the following project:

<Project Sdk="Microsoft.NET.Sdk">

  <PropertyGroup>
    <OutputType>Exe</OutputType>
    <TargetFramework>netcoreapp3.1</TargetFramework>
  </PropertyGroup>

  <ItemGroup>
    <COMReference Include="Microsoft.Office.Access.dll">
      <Guid>4affc9a0-5f99-101b-af4e-00aa003f0f07</Guid>
      <VersionMajor>9</VersionMajor>
      <VersionMinor>0</VersionMinor>
      <WrapperTool>tlbimp</WrapperTool>
      <Lcid>0</Lcid>
      <Isolated>false</Isolated>
      <Private>true</Private>
    </COMReference>
  </ItemGroup>
  <ItemGroup>
    <COMReference Include="Microsoft.Office.Access.Dao.dll">
      <Guid>4ac9e1da-5bad-4ac7-86e3-24f4cdceca28</Guid>
      <VersionMajor>12</VersionMajor>
      <VersionMinor>0</VersionMinor>
      <WrapperTool>tlbimp</WrapperTool>
      <Lcid>0</Lcid>
      <Isolated>false</Isolated>
    </COMReference>
  </ItemGroup>

</Project>

Publish the project (with full MSBuild because that is needed for COMReference support): msbuild /restore /t:publish

Expected

Microsoft.Office.Access.dll and Microsoft.Office.Access.Dao.dll are both present in the publish folder

Actual

Neither is in the output folder, but a file with the names mashed together is: Interop.Microsoft.Office.Interop.Access.dll;Interop.Microsoft.Office.Interop.Access.Dao.dll

Analysis

It appears that the @ needs to be replaced by % here: https://github.com/dotnet/sdk/blob/ac7fd98a7b6f8e625aab8977029813bec6088e70/src/Tasks/Microsoft.NET.Build.Tasks/targets/Microsoft.NET.Publish.targets#L528

Original issue description

With release 16.5 and SDK 3.1.200 the problem still exists !!! Now the dll name will corrupted

Why you don’t fix this with the new release ???

Interop.Microsoft.Office.Interop.Access.dll;Interop.Microsoft.Office.Interop.Access.Dao.dll;Interop.Microsoft.Office.Core.dll

only one file is copyed with all names inside !!!

Severity Code Description Project File Line Suppression State Error MSB3094 “DestinationFiles” refers to 3 item(s), and “SourceFiles” refers to 1 item(s). They must have the same number of items. Esi.Bootstrap.Package C:\Program Files (x86)\Microsoft Visual Studio\2019\Preview\MSBuild\Microsoft\DesktopBridge\Microsoft.DesktopBridge.targets 692

  <Target Name="_CopyPackageFiles" DependsOnTargets="_ConvertItems">
    <Copy SourceFiles="%(File.FullPath)" DestinationFiles="%(File.CopyToTargetPath)" Condition="%(File.CopyToTargetPath) != ''"/>

    <ItemGroup>
      <FileWrites Include="%(File.CopyToTargetPath)" Condition="%(File.CopyToTargetPath) != ''" />
    </ItemGroup>
  </Target>

I created a new .net core wpf application and add a com dependency.

<Project Sdk="Microsoft.NET.Sdk.WindowsDesktop">

  <PropertyGroup>
    <OutputType>WinExe</OutputType>
    <TargetFramework>netcoreapp3.1</TargetFramework>
    <UseWPF>true</UseWPF>
  </PropertyGroup>

  <ItemGroup>
    <COMReference Include="Microsoft.Office.Access.dll">
      <Guid>4affc9a0-5f99-101b-af4e-00aa003f0f07</Guid>
      <VersionMajor>9</VersionMajor>
      <VersionMinor>0</VersionMinor>
      <WrapperTool>tlbimp</WrapperTool>
      <Lcid>0</Lcid>
      <Isolated>false</Isolated>
      <Private>true</Private>
    </COMReference>
  </ItemGroup>

</Project>

On publishing to folder the COM+ reference dll will not copyed to the publishing folder.

WpfApp1.zip

[sidatacom]

Sounds good I’m excited !

[dsplaisted]

@sidatacom This will be fixed in Visual Studio 16.6. It should likely make its way into preview versions of the 3.1.300 .NET Core SDK in the next few days. You can download the preview from the links in the table here: https://github.com/dotnet/installer/