Property in 2 names, better to have bought or gifted?

[NameChangedAgain5000]

person A originally owned a property - put in joint names with person b

if person a was to die, would it be better for person b to have 'paid' for the part of the property, or to have been gifted it, or does it make no difference

Also - if person A made a will and then got married and then died, what happens there? is the will null? does the widow(er) get everything?

Think it depends how property was registered - joint tenants or tenants in common.

I don't know, just person b is now on the deeds

If they are gifted it , the value would be taken into account for inheritance tax assessment were the gifter to die within 7 years.