implying by this question (and in other posts you have implied) that no Arab armies attacked any Israeli territory - that all the attacks were on areas that should have been part of the Palestinian state. So I've just pointed out a few Israeli areas that were attacked by Arab armies in 1948. And yes, you're quite right once a war has started one is permitted to attach the other side. That's why, as you point out in that farce of a site you cite, the UN resolutions regarding the armistice refer to the Israeli army withdrawing from areas in Palestine. Once the Yishuv was attacked, it carried the battle onto it opponents territory.
Boko Haram extremists kill 26, including children (AP)
from the article: U.S.: Easing Gaza siege would help counter Goldstone