pickblock addition for survival

When playing on my friends SMP, I build a lot with dirt and cobblestone. But most of the time there is no dirt or cobblestone around, but instead grass blocks and stone. So i thought it would be a cool addition to the pickblock  mechanic that if you are in survival, and you dont have the block you are trying to pickblock, you pickblock the block from the loottable instead. so for example: If you pickblock stone in survival but you only have cobblestone, cobblestone gets pickblocked instead of stone. Another example: you want to terraform an area (in survival) with no dirt blocks in sight, but you only have dirt on you. if you then try to pickblock grass blocks, dirt gets pickblocked instead. Like wise, you could pickblock normal grass to pickblock seeds, coal ore for coal, clay blocks for clay, etc. I really hope this will be discussed with the team. Thanks in advance!