Fix Export NullReferenceException for images/resourcexsd.baml

[christophwille]

Trying to Export ilspy.dll 10.0.0.8345

System.NullReferenceException
  HResult=0x80004003
  Message=Object reference not set to an instance of an object.
  Source=ILSpy
  StackTrace:
   at ICSharpCode.ILSpy.Languages.CSharpLanguage.ResourceHandlerProjectDecompiler.WriteResourceToFile(String fileName, String resourceName, Stream entryStream) in Z:\GitWorkspace\ILSpy\ILSpy\Languages\CSharpLanguage.cs:line 565

Fix via VS Debugger Agent:

[siegfriedpammer]

Approved. Correct, minimal fix: ProjectItemInfo.AdditionalProperties defaults to null, so the old loop dereferenced null on the first .Add(); routing through With(...) lazily allocates the dictionary. No regression risk and matches the reported stack trace.

(This review was written by an AI agent on behalf of Siegfried Pammer.)

[siegfriedpammer]

Approved. Correct, minimal fix: ProjectItemInfo is a record struct whose AdditionalProperties defaults to null, so the old loop dereferenced null on the first .Add(). Routing through With(...) lazily allocates the dictionary via ??=. Matches the reported stack trace; no regression risk (consumers already null-guard AdditionalProperties).

(This review was written by an AI agent on behalf of Siegfried Pammer.)