Make the GlobalStyleComponent call the base constructor with props. (#2321)

* Make the GlobalStyleComponent call the base constructor with props.

* Changelog tweak.

* Simplify Flow types.

* Add PR link to the changelog entry.

CHANGELOG.md

@@ -6,6 +6,8 @@ _The format is based on [Keep a Changelog](http://keepachangelog.com/) and this
 
 ## Unreleased
 
+- Make the `GlobalStyleComponent` created by `createGlobalStyle` call the base constructor with `props` (see [#2321](https://github.com/styled-components/styled-components/pull/2321)).
+
 ## [v4.1.2] - 2018-11-28
 
 - Fix function-form attrs to receive the full execution context (including theme) (see [#2210](https://github.com/styled-components/styled-components/pull/2210))

src/constructors/createGlobalStyle.js

@@ -12,6 +12,8 @@ import css from './css';
 
 import type { Interpolation } from '../types';
 
+type GlobalStyleComponentPropsType = Object;
+
 // place our cache into shared context so it'll persist between HMRs
 if (IS_BROWSER) {
   window.scCGSHMRCache = {};
@@ -25,15 +27,15 @@ export default function createGlobalStyle(
   const id = `sc-global-${hashStr(JSON.stringify(rules))}`;
   const style = new GlobalStyle(rules, id);
 
-  class GlobalStyleComponent extends React.Component<*, *> {
+  class GlobalStyleComponent extends React.Component<GlobalStyleComponentPropsType, *> {
     styleSheet: Object;
 
     static globalStyle = style;
 
     static styledComponentId = id;
 
-    constructor() {
-      super();
+    constructor(props: GlobalStyleComponentPropsType) {
+      super(props);
 
       const { globalStyle, styledComponentId } = this.constructor;