Declaration merging conflicts when using export statement

[aleung]

TypeScript Version: 1.8.10 & 2.0.0@beta

I follow the example in Module Augmentation and write below code. The only different is that I use export statement in someclass.ts.

// someclass.ts
class SomeClass {
}
export {SomeClass}

// augmented.ts
import { SomeClass } from "./someclass";
declare module "./someclass" {
  interface SomeClass {
    hello(): void;
  }
}
SomeClass.prototype.hello = function() {
  return this;
}

// consumer.ts
import { SomeClass } from "./someclass";
import "./augmented";
new SomeClass().hello();

It gives compile error:

augmented.ts(7,1): error TS2304: Cannot find name 'SomeClass'.
consumer.ts(3,5): error TS2304: Cannot find name 'SomeClass'.
someclass.ts(6,1): error TS2484: Export declaration conflicts with exported declaration of 'SomeClass'

I change back someclass.ts to use declaration export, then compile success.

// someclass.ts
export class SomeClass {
}

Suppose two export forms should behave the same. Is it a bug?

[mhegazy]

Duplicate of #9127