anchor.diff:              // If part of the method body is in another document returns nil handle.
               let tryGetSingleDocumentIndex =
                   let mutable singleDocumentIndex = 0
  -                for i in 1 .. sps.Length - 1 do
  +                for i in 0 .. sps.Length - 1 do
                       let index = sps.[i].Document
                       if index <> singleDocumentIndex then 
                           singleDocumentIndex <- index
                   singleDocumentIndex
   
  -            if sps.Length = 0 then 
  +            // Filter out feefee (Hidden) sequence points
  +            let sps = sps |> Array.filter(fun sp -> sp.Line <> 0xfeefee && sp.EndLine <> 0xfeefee)
  +
  +            if sps.Length = 0 then
                   Unchecked.defaultof<DocumentHandle>, Unchecked.defaultof<BlobHandle>
               else
  -                let builder = new BlobBuilder()
  -                builder.WriteCompressedInteger(minfo.LocalSignatureToken)
  -
                   let mutable previousNonHiddenStartLine = -1
                   let mutable previousNonHiddenStartColumn = -1
                   let mutable previousDocumentIndex = -1
                   let mutable singleDocumentIndex = tryGetSingleDocumentIndex
                   let mutable currentDocumentIndex = previousDocumentIndex
   
  +                let builder = new BlobBuilder()
  +                builder.WriteCompressedInteger(minfo.LocalSignatureToken)
  +
                   for i in 0 .. (sps.Length - 1) do
  -
                       if previousDocumentIndex <> currentDocumentIndex then
                           // optional document in header or document record:
                           if previousDocumentIndex <> -1   then
  
positive.code:                     else
                          builder.WriteCompressedInteger(sps.[i].Offset)
  
                          // F# does not support hidden sequence points yet !!!
                          // if (sequencePoints[i].IsHidden)
                          // {
                          //     builder.WriteInt16(0);
                          //     continue;
                          // }
  
                      let deltaLines = sps.[i].EndLine - sps.[i].Line;
                      let deltaColumns = sps.[i].EndColumn - sps.[i].Column;
                      builder.WriteCompressedInteger(deltaLines);
  
                      if deltaLines = 0 then 
                          builder.WriteCompressedInteger(deltaColumns)
  
negative.code:             index.Add(doc.File, handle)
          index
  
      let mutable lastLocalVariableHandle = Unchecked.defaultof<LocalVariableHandle>
      metadata.SetCapacity(TableIndex.MethodDebugInformation, info.Methods.Length)
      info.Methods |> Array.iteri (fun _i minfo ->
          let docHandle, sequencePointBlob =
  