The OP of the question Why does my graphics flows out of the box? seems to no longer exist while there is an answer with a working solution. Therefore the question will stay open forever. This happens from time to time, and there are also one-time users which ask a single question and never return to this site to accept an answer.
I would resolve these questions the following way:
A dummy account with an appropriate name and description should be created y the moderators. It then can be used to ask the same question again and merge the original question with it. This moves all answers to the new question while keeping all votes etc. Then the/an answer can be accepted. This effectively takes over the question to a new account. The question copy might be made CW.
This should only be done in specific cases when:
- The OP's account got deleted
- The question got migrated here and the the OP never signed up here for a specific time (say 3 month to make sure the question is really "old")
- The OP is a new unregistered user and never really returned to the question (for again 3 month or so)
Of course, if applicable, the OP should first be contacted using a comment and asked to accept an answer or state what is still missing.