Webpack: Tree shaking doesn't work with "export * from 'module'"

[Mithras]

I'm submitting a bug report

Webpack version:
2.1.0-beta.20

Current behavior:
Tree shaking works with re-exports like "export { something } from 'module'" but doesn't work with "export * from 'module'".

Expected/desired behavior:
Tree shaking works with any kind of re-export.

• If the current behavior is a bug, please provide the steps to reproduce and if possible a minimal demo of the problem along with a gist/jsbin of your webpack configuration.

app/
    my-feature/
        func12.js
        func34.js
        index.js
    main.js

func12.js

export function func1() { console.log("func1") }
export function func2() { console.log("func2") }

func34.js

export function func3() { console.log("func3") }
export function func4() { console.log("func4") }

index.js

export * from "./func12"
export * from "./func34"

main.js

import { func1, func3 } from "./my-feature"

func1();
func3();

• What is the expected behavior?
  Only func1() and func3() should be exported.
  func2() and func4() should not, they should be marked as "unused harmony export"

[Mithras]

Also, changing index.js like this

export { func1, func2 } from "./func12"
export { func3, func4 } from "./func34"

solves the problem, but I can't change all the third party modules to follow that rule.

[vladshcherbin]

Same bug unfortunately, tree shaking is not working with export * from.

[sokra]

We'll fix it..