Apply suggestion from @baronfel

Author: baronfel

src/Tasks/Microsoft.NET.Build.Tasks/targets/Microsoft.NET.Sdk.DefaultItems.targets

@@ -35,8 +35,9 @@ Copyright (c) .NET Foundation. All rights reserved.
     <DefaultItemExcludes>$(DefaultItemExcludes);$(BaseOutputPath)/**</DefaultItemExcludes>
     <!-- obj folder, by default -->
     <DefaultItemExcludes>$(DefaultItemExcludes);$(BaseIntermediateOutputPath)/**</DefaultItemExcludes>
-    <!-- Exclude PublishDir to prevent published artifacts from being included in subsequent builds/publishes.
-         This is especially important for file-based apps where PublishDir is set to ./artifacts/<appname> next to the app file. -->
+    <!-- Exclude PublishDir to prevent published artifacts from being included in subsequent builds/publishes. 
+         While in most cases PublishDir is contained within BaseOutputPath or BaseIntermediateOutputPath,
+         this is by no means required, so we should protect against this happening here. -->
     <DefaultItemExcludes Condition="'$(PublishDir)' != ''">$(DefaultItemExcludes);$(PublishDir)/**</DefaultItemExcludes>
 
     <!-- Various files that should generally always be ignored -->