What are the tax implications after selling a stock that went through a reverse stock split (new ticker, CUSIP) or merger?

If I bought and held a stock for one year, what happens to my tax liability when it goes through a reverse stock split and gets a new ticker name?

Is the original stock considered sold on the reverse split date?

Is the new ticker name considered my new buy date on that stock? If I sell the stock the next day, would that be considered a short-term buy and subject to short-term capital gains tax? Or does the fact that I held the stock for over a year prior get considered?