A strange gooseberry?

Half my new-ish allotment remains untouched and wild (2 years of neglect). There is a huge bush in the middle, 5 feet high and 7 or so across. It has sprouted berries which look like gooseberries to me, although they are not hairy. The bush also has no thorns, but the leaves look gooseberry-ish.   Is this some weird type of gooseberry? Or something else I'm not familiar with?

It'll be a jostaberry or Caseille - a gooseberry x blackcurrant

Lovely, I wish I'd inherited one of those 

Blackbirds rather like them, so netting it will mean you get some of the fruit for yourself