unusedArguments incorrectly removes argument when same variable name is used in an if let

[fivegreenapples]

I found this fairly minimal test case causes the number argument to be stripped incorrectly by unusedArguments:

   func doSomething(with number: Int) {
        if let number = Int?(123),
           number == 456
        {
            print("Not likely")
        }

        if number == 180 {
            print("Bullseye!")
        }
    }

Interestingly, if you remove the number == 456 it parses fine. i.e. this is left untouched and compiles:

    func doSomething(with number: Int) {
        if let number = Int?(123) {
            print("Not likely")
        }

        if number == 180 {
            print("Bullseye!")
        }
    }

[nicklockwood]

@fivegreenapples fixed in 0.51.13

[fivegreenapples]

Awesome! Thank you!

[FelixLisczyk]

I have the same problem in 0.51.13. Should I create a new issue?

Example:

private func isValid(indexPath: IndexPath?) {
    if let indexPath, indexPath.row < self.tableView.numberOfRows(inSection: 0) {
        return true
    } else {
        return false
    }
}