Is it...or Isn't it?

There is a vine in our backyard that I was sure was a passion fruit vine. It climbs and curves and twists like a passionfruit vine and the leaves are similar. 

Last spring/summer it grew wildly but no fruit or flower eventuated and it kinda looked a little sad in the winter. But again this year it has pepped up and making its way around the fence it is against and suddenly it has created lovely exotic looking flowers.

And I always thought that if it flowered it fruited, or was it the other way around - flower then no fruit?? hmmm

BUT there is a discussion on whether it really is a passionfruit vine or not!

Is this a flower of a passionfruit??