I received a one year visa a while ago but since my passport expires before one year, my visa expires in nine months.

First they stamped it 12 months out, then made some mistake and crossed that out then put in a date 9 months out.

I'm getting my passport renewed now and then getting a multiple entry stamp.

How does it work when your visa is in your old passport and you get a new passport?

I'm guessing the reentry stamp will be made in the new passport but what about the visa?

Since my passport will be valid for ten years, any chance in hell that they'll put the original 12 month from issuance date in my new passport?

I assume that you are on an extension of stay. When you get your new passport make sure that you get a letter from your embassy verifying that they have issued you a new passport. Take the letter and both passport to immigration and they will transfer the extension to the new passport. In the past they would give you the extra time but that stopped a few months ago so they will only give you to the current expiration date and you will have to apply for another extension before it expires. The reentry permit will be in the new passport as your old one has been cancelled.

They will just give you the current 9 months in the new passport and yor re-entry permit will also be valid for tht time. Once those 9 months expire you willl have to apply for a new extension of stay, which then will be again for 1 year.