[v2] ThemeProvider is broken on IE <= 10

Version

2.0.0-17

Reproduction

import React from 'react';
import styled from 'styled-components';

const Title = styled.h1`
  font-size: 2em;
  color: ${props => props.theme.color || '#e2e2e2'};
`;

Expected Behavior

The Title component should have the color passed in the ThemeProvider.

Actual Behavior

The default value is being applied since the theme object is empty.

This works on 1.4.6. Maybe the fix on PR #379 (issue #355) is not applied on v2?

[kitten]

@anton6 It is already as v2.0.0-19 or under @rc tag. The official release of v2 will be very soon

[kitten]

Seemed simple enough. This should fix it https://github.com/styled-components/styled-components/pull/807

I’m not even sure if we should support IE <= 10, but if it comes in such a “cheap package” it’s ok I guess.