TMemoryStream object leak in UBlockChain.pas: class function TPCOperation.GetOperationFromStreamData

[SkybuckFlying]

Potential TMemoryStream object leak found. See ***.

TMemoryStream may not be freed if exited.

See line 3879 in UBlockChain.pas

class function TPCOperation.GetOperationFromStreamData(AUseV5EncodeStyle : Boolean; ACurrentProtocol: word; StreamData : TBytes): TPCOperation;
  // Loads an TPCOperation saved using "GetOperationStreamData"
  // For compatiblity will allow V4..V5 encode stype
  // Old V4: 1 byte for OpType
  // New V5: 2 bytes for OpType and 2 bytes for ProtocolVersion
  // N bytes for Operation specific data (saved at SaveOpToStream)
  //
  // NOTE:
  // AFTER V5 activation, all nodes must use new AUseV5EcnodeStyle = TRUE
Var stream : TStream;
  b : Byte;
  j: Integer;
  OpClass: TPCOperationClass;
  auxOp: TPCOperation;
  LOpType, LOperationProtocolVersion : Word;
begin
  Result := Nil;
  stream := TMemoryStream.Create;
  Try
    stream.WriteBuffer(StreamData[0],Length(StreamData)); // Fixed bug 4.0.0
    stream.Position := 0;

    if (AUseV5EncodeStyle) then begin
      // 2 bytes (UInt16) for OpType
      // 2 bytes (UInt16) for ProtocolVersion
      Stream.Read(LOpType,2);
      Stream.Read(LOperationProtocolVersion,2);
      if (LOperationProtocolVersion<=0) or (LOperationProtocolVersion>CT_BUILD_PROTOCOL) then Exit;
    end else begin
      // 1 bytes (UInt8) for OpType
      // Fixed ProtocolVersion = 4
      stream.Read(b,1);
      LOpType := b;
      LOperationProtocolVersion:=ACurrentProtocol;
    end;

    j := TPCOperationsComp.IndexOfOperationClassByOpType(LOpType);
    if j >= 0 then
      OpClass := _OperationsClass[j]
    else Exit;  // *** POTENTIAL OBJECT LEAK ***
    auxOp := OpClass.Create(LOperationProtocolVersion);
    if auxOp.LoadOpFromStream(stream,False) then Result := auxOp
    else auxOp.Free;
  Finally
    stream.Free;  // *** NEVER CALLED IF EXIT ***
  End;
end;