Is the husband obligated to pay his wife a new dowry or mahr after being absent from her for a year abroad?

If a man is absent from his wife for a year and does not divorce her, it is not permissible for him to enter into a new marriage contract or give a new dowry, because she is still his wife. However, if he divorces her with a first or second revocable divorce and her waiting period (iddah) has ended, she does not become lawful for him again except with a new contract, a new dowry, a guardian (wali), and two witnesses. The husband must not be absent from his wife for more than six months without her consent, in accordance with what was narrated from Umar (may Allah be pleased with him).