Under Israeli law "Jerusalem" is whatever Israel says it is. But here's the trick: Israel has left that decision to anonymous pen-pushers, not to the Knesset. After all, the "municipality of Jerusalem" was unilaterally expanded by administrative fiat immediately after the Six Day War. Get it? If a pen-pushing nobody can announce that "today Jerusalem is a looooot bigger than it was yesterday" then that same decision can be reversed tomorrow by Yet Another Administrative Fiat. At which point: a) Israel can relinguish that territory b) and still have an "undivided Jerusalem" c) because that territory "isn't Jerusalem any more" As Easy As, once you understand the trick.
Palestinian man suffers light wounds from rocks thrown by Jewish men in Jerusalem (Haaretz)
from the article: Lieberman: Jerusalem is our eternal capital, it will never be divided