Hawzah News Agency – A person who reaches a fruit tree while passing by - on the following conditions - can eat its fruit:
1. As a precaution, not to be sure of the owner's dissatisfaction.
2. To pass by accidentally not with the intention to eat fruit.
3. Not to damage the tree nor waste the fruits.
4. To eat the fruit there and not to take it with himself.
5. Not to enter the property - such as a garden.

Source: https://www.leader.ir/en/book/32/Practical-Laws-of-Islam