Able to add fields in invoices without item name

Hey I dont think users should be able to add fields in the invoices without an item name. I just entered spaces on the item name and item name field isn't treating it as empty string. Also I am able to enter quantities in points like 0.1, 0.3 and even 0. I think that too shouldn't be allowed because quantities in points or 0 doesn't make sense. This is a minor bug which needs to be fixed. Can you assign this to me so I can fix this bug?