Transform paths when using git's tar on Windows

- also narrow `tar` workaround to Microsoft.AspNetCore.App.Ref project
  - not needed in Microsoft.AspNetCore.App.Runtime project

Author: dougbu

src/Framework/Directory.Build.props

@@ -6,13 +6,6 @@
     <!-- Shared between targeting pack and runtime build. -->
     <PlatformManifestFileName>PlatformManifest.txt</PlatformManifestFileName>
     <PlatformManifestOutputPath>$(ArtifactsObjDir)$(PlatformManifestFileName)</PlatformManifestOutputPath>
-
-    <!-- Work around issues finding the `tar` command on CI machines. -->
-    <TarCommand>tar</TarCommand>
-    <TarCommand Condition="'$(OS)' == 'Windows_NT'">C:\Windows\System32\tar.exe</TarCommand>
-    <TarCommand Condition="'$(OS)' == 'Windows_NT' AND !Exists('$(TarCommand)')">C:\Program Files\Git\usr\bin\tar.exe</TarCommand>
-    <TarCommand Condition="'$(OS)' == 'Windows_NT' AND !Exists('$(TarCommand)')">C:\Program Files (x86)\Git\usr\bin\tar.exe</TarCommand>
-    <TarCommand Condition="'$(OS)' == 'Windows_NT'">&quot;$(TarCommand)&quot;</TarCommand>
   </PropertyGroup>
 
   <ItemGroup>

src/Framework/ref/Microsoft.AspNetCore.App.Ref.csproj

@@ -169,13 +169,30 @@ This package is an internal implementation of the .NET Core SDK and is not meant
           Inputs="@(RefPackContent)"
           Outputs="$(ZipArchiveOutputPath);$(TarArchiveOutputPath)"
           Condition="'$(IsPackable)' == 'true'">
+    <PropertyGroup>
+    <!-- Work around issues finding the `tar` command on CI machines. -->
+      <TarCommand>tar</TarCommand>
+      <TarCommand
+          Condition="'$(OS)' == 'Windows_NT' AND Exists('$(SystemRoot)\System32\tar.exe')">"$(SystemRoot)\System32\tar.exe"</TarCommand>
+      <TarCommand
+          Condition="'$(OS)' == 'Windows_NT' AND Exists('$(ProgramFiles)\Git\usr\bin\tar.exe')">"$(ProgramFiles)\Git\usr\bin\tar.exe"</TarCommand>
+      <TarCommand
+          Condition="'$(OS)' == 'Windows_NT' AND Exists('$(MSBuildProgramFiles32)\Git\usr\bin\tar.exe')">"$(MSBuildProgramFiles32)\Git\usr\bin\tar.exe"</TarCommand>
+
+      <!-- For the tar packed with git, transform e.g. "C:\root\AspNetCore\File.tar.gz" to "/C/root/AspNetCore/File.tar.gz". -->
+      <_TarArchiveOutputPath>$(TarArchiveOutputPath)</_TarArchiveOutputPath>
+      <_TarArchiveOutputPath
+          Condition="$(TarCommand.Contains('\Git\'))">/$(TarArchiveOutputPath.Replace('\','/').Replace(':',''))</_TarArchiveOutputPath>
+    </PropertyGroup>
+
     <ZipDirectory
       SourceDirectory="$(TargetingPackLayoutRoot)"
       DestinationFile="$(ZipArchiveOutputPath)"
       Overwrite="true" />
+
     <!-- Requires Windows 10 version 1803 or newer -->
     <Exec
-      Command="$(TarCommand) -czf $(TarArchiveOutputPath) ."
+      Command="$(TarCommand) -czf $(_TarArchiveOutputPath) ."
       WorkingDirectory="$(TargetingPackLayoutRoot)" />
     <Message Importance="High" Text="$(MSBuildProjectName) -> $(TarArchiveOutputPath)" />
   </Target>

src/Framework/src/Microsoft.AspNetCore.App.Runtime.csproj

@@ -371,7 +371,7 @@ This package is an internal implementation of the .NET Core SDK and is not meant
 
     <!-- Extract the dotnet-runtime archive -->
     <Exec Condition="'$(ArchiveExtension)' == '.tar.gz'"
-      Command="$(TarCommand) -xzf $(DotNetRuntimeArchive) -C $(RedistSharedFrameworkLayoutRoot)" />
+      Command="tar -xzf $(DotNetRuntimeArchive) -C $(RedistSharedFrameworkLayoutRoot)" />
 
     <Unzip Condition="'$(ArchiveExtension)' == '.zip'"
       SourceFiles="$(DotNetRuntimeArchive)"
@@ -436,7 +436,7 @@ This package is an internal implementation of the .NET Core SDK and is not meant
       Overwrite="true"
       Condition="'$(ArchiveExtension)' == '.zip'" />
     <Exec
-      Command="$(TarCommand) -czf $(InternalArchiveOutputPath) ."
+      Command="tar -czf $(InternalArchiveOutputPath) ."
       WorkingDirectory="$(SharedFrameworkLayoutRoot)"
       Condition="'$(ArchiveExtension)' == '.tar.gz'" />
   </Target>
@@ -453,7 +453,7 @@ This package is an internal implementation of the .NET Core SDK and is not meant
       Overwrite="true"
       Condition="'$(ArchiveExtension)' == '.zip'" />
     <Exec
-      Command="$(TarCommand) -czf $(RedistArchiveOutputPath) ."
+      Command="tar -czf $(RedistArchiveOutputPath) ."
       WorkingDirectory="$(RedistSharedFrameworkLayoutRoot)"
       Condition="'$(ArchiveExtension)' == '.tar.gz'" />
   </Target>