Al-Sha'bi narrates from Masruq, or he said: I think it is from Masruq, that he said: Had Sayyiduna Umar (may Allah be pleased with him) not given the missing husband the choice between his wife and the dowry, I would have held that he has more right to her when he comes back.
Imam al-Shafi'i (may Allah have mercy on him) said that Sayyiduna Ali bin Abi Talib (may Allah be pleased with him) said: The wife of the missing husband is a woman who has been put to trial; let her be patient and not marry until certain news of his death reaches her. Imam al-Shafi'i (may Allah have mercy on him) said: This is what we hold.
Imam al-Bayhaqi (may Allah have mercy on him) said: Qatadah narrated it from Khilas bin Amr and from Abu al-Malih, from Sayyiduna Ali (may Allah be pleased with him), that he said: When her first husband comes, he is given the choice between the latter dowry and his wife.
The narration of Khilas from Sayyiduna Ali (may Allah be pleased with him) is weak, and Abu al-Malih did not hear it from Sayyiduna Ali (may Allah be pleased with him).
Hadith Referenceالسنن الكبرى للبيهقي / كتاب العدد / 15574