autoindent commented out lines

// let's begin with this function. f() was previously commented out using Cmd--
function context() {
    if (foo) {
//        f();
        g();
    }
}


// we remove the if-statement and let its block run unconditionally instead.
// Cmd-x to delete leading and trailing line, CmdAlt-I to reindent the two remaining one by one:
function context() {
//        f();
    g();
}


// if the two remaining are reindented both at the same time, the result is this instead:
function context() {
    //        f();
    g();
}


// but this is what i want and end up doing manually:
function context() {
//    f();
    g();
}

Hello! So you want there to be the same number of spaces between // and f() as before g(), right?
You know that in both cases if you uncomment that line you'll have to auto-indent the code again to get the right formatting? Sorry for all the questions, I'm just a bit confused why you prefer that way of indentation.