Translation:Let me know when you come to Germany.
as Ektoraksan said, we would assume the first part (gelince) refers to the same person as the second part (ver). I think nobody would ever say the sentence above if they were talking about a 3rd person. When there are 2 subjects, you don't omit the pronouns, definitely not both. We would then say "O Almanya'ya gelince (sen) bana haber ver"