fix nil handling for histry readin
fix nil handling for histry readin

mergermarket/dashing-contrib,vStone/dashing-contrib,osterzel/dashing-contrib,osterzel/dashing-contrib,vStone/dashing-contrib,QubitProducts/dashing-contrib,mergermarket/dashing-contrib,mergermarket/dashing-contrib,vStone/dashing-contrib,osterzel/dashing-contrib,QubitProducts/dashing-contrib,QubitProducts/dashing-contrib