fix issue with `PwshPath`

Make sure MSI build works when not preview (#7752)
The variable was set to empty (meaning to delete the variable) in the non-preview case and the build fails. The fix avoids setting the variable to empty
The variable was set to empty (meaning to delete the variable) in the non-preview case and the build fails. The fix avoids setting the variable to empty
PowerShell · TravisEz13 · Sep 10, 2018 · TravisEz13 · Sep 10, 2018 · TravisEz13
diff --git a/assets/Product.wxs b/assets/Product.wxs
@@ -165,7 +165,7 @@
            <!-- add ourselves to %PATH% so pwsh.exe can be started from Windows PowerShell or cmd.exe -->
            <Component Id="SetPath" Guid="{9dbb7763-7baf-48e7-b025-3bdedcb0632f}" KeyPath="yes">
              <Condition>ADD_PATH=1</Condition>
-              <Environment Id="PATH" Action="set" Name="PATH" Part="last" Permanent="no" System="yes" Value="[$(var.ProductDirectoryName)]$(var.PwshPath)"/>
+              <Environment Id="PATH" Action="set" Name="PATH" Part="last" Permanent="no" System="yes" Value="$(var.PwshPath)"/>
diff --git a/tools/packaging/packaging.psm1 b/tools/packaging/packaging.psm1
        [Environment]::SetEnvironmentVariable("UpgradeCodeX64", '31ab5147-9a97-4452-8443-d9709f0516e1', "Process")
        [Environment]::SetEnvironmentVariable("UpgradeCodeX86", '1d00683b-0f84-4db8-a64f-2f98ad42fe06', "Process")
        [Environment]::SetEnvironmentVariable("IconPath", 'assets\Powershell_black.ico', "Process")
    }
    else
    {
-        [Environment]::SetEnvironmentVariable("PwshPath", 'preview', "Process")
+        [Environment]::SetEnvironmentVariable("PwshPath", "[$productDirectoryName]preview", "Process")