The Road will only have a 'happy' ending if you know how to see it.
The fact that The Boy never adopts the out-and-out mistrust of The Man and accepts the help of a stranger which may lead to The Boy to having a better life overall.
i wanted to a HAppy ending as in farm food etc etc. although i knew it would / could not happen.
you are so correct about the boy's trusting nature compared to his father.
what was scary was the fact the boy resembled his mother ( charlize theron ) so much, as in real life