anchor.diff:     result:=PrefilterRootNode.SQLExpression(Field);
     end;
    finally
  -  CriticalSection.Leave;
  +  ParallelLockLeave(@ParallelLock);
    end;
    if length(result)=0 then begin
     result:='('+Field+' LIKE "%")';
  
positive.code:    end;
    end;
   finally
    CriticalSection.Leave;
   end;
  end;
  
  function TFLRE.GetPrefilterSQLExpression(Field:ansistring):ansistring;
  begin
   result:='';
   CriticalSection.Enter;
   try
    if not HasPrefilter then begin
     PrefilterRootNode:=CompilePrefilterTree(AnchoredRootNode);
  
negative.code:    result:=true;
    end;
   finally
    ParallelLockLeave(@ParallelLock);
   end;
  end;
  
  