Layout Panel is not resizing after closing Sidebar with percentage width

[amosyuen]

I'm using 2.0.0-beta.12. When I create a layout as such:

<Layout>
        <Panel>
          <Map />
          <Button
            icon={<MdCode />}
            onClick={this.toggleSidebar}
            styleName="toggle"
          />
        </Panel>
        <Sidebar pinned={this.state.showSideBar} scrollY width={50}>
          <List />
        </Sidebar>
      </Layout>

The side bar starts off at 50%, then when I click the button which toggles the pinned status of the side bar the side bar hides, but the panel doesn't resize and is stuck at 50% width.

If I change the sidebar width to a value between 1-12, then the panel resizes correctly.

[ulfryk]

I get same issue with 2.0.0-beta.13