Broken encapsulation in mixed classes with redeclared props

[tsofist]

TypeScript Version: 2.2.0-dev.20170202

#13743

Code

type Constructor<T> = new(...args: any[]) => T;

class A {
 public pb: number = 2;
 protected ptd: number = 1;
 private pvt: number = 0;
}

function mixB<T extends Constructor<{}>>(Cls: T) {
 return class extends Cls {
 protected ptd: number = 10; //override
 private pvt: number = 0; //hiding try
 };
}

function mixB2<T extends Constructor<A>>(Cls: T) {
 return class extends Cls {
 protected ptd: number = 10; //override
 //private pvt: number = 0; //hiding try failded: TS2415
 };
}

const
 AB = mixB(A),
 AB2 = mixB2(A);

function mixC<T extends Constructor<{}>>(Cls: T) {
 return class extends Cls {
 protected ptd: number = 100; //override
 private pvt: number = 0; //hiding try
 };
}

const
 AB2C = mixC(AB2),
 ABC = mixC(AB);

const
 a = new A(),
 ab = new AB(),
 abc = new ABC(),
 ab2c = new AB2C();

Expected behavior:

a.pb.toFixed(); //ok
a.ptd.toFixed(); //error: TS2445
a.pvt.toFixed(); //error: TS2341

ab.pb.toFixed(); //ok
ab.ptd.toFixed(); //error: TS2445
ab.pvt.toFixed(); //error: TS2341

abc.pb.toFixed(); //ok
abc.ptd.toFixed(); //error: TS2445
abc.pvt.toFixed(); //error: TS2341

ab2c.pb.toFixed(); //ok
ab2c.ptd.toFixed(); //error: TS2445
ab2c.pvt.toFixed(); //error: TS2341

Actual behavior:

a.pb.toFixed(); //ok
a.ptd.toFixed(); //ok error: TS2445
a.pvt.toFixed(); //ok error: TS2341

ab.pb.toFixed(); //ok
ab.ptd.toFixed(); //ok =(
ab.pvt.toFixed(); //ok =(

abc.pb.toFixed(); //ok
abc.ptd.toFixed(); //ok =(
abc.pvt.toFixed(); //ok =(

ab2c.pb.toFixed(); //ok
ab2c.ptd.toFixed(); //ok =(
ab2c.pvt.toFixed(); //ok =(