Backport #3568 (Read from textContent rather than innerHTML during re…

…hydrate) to v5 (#3591)

* Backport #3568 to v5

* Describe innerHTML to textContent change

Co-authored-by: Keegan Street <keegan.street@rea-group.com>

CHANGELOG.md

@@ -6,6 +6,8 @@ _The format is based on [Keep a Changelog](http://keepachangelog.com/) and this
 
 ## Unreleased
 
+- Rehydrate stylesheets from `textContent` rather than `innerHTML` to fix issue of selectors sometimes being HTML encoded (see [#3567](https://github.com/styled-components/styled-components/issues/3567)).
+
 ## [v5.3.1] - 2021-08-24
 
 - Fix forced server-side mode not triggering global styles (See [#3566](https://github.com/styled-components/styled-components/pull/3566))

packages/styled-components/src/sheet/Rehydration.js

@@ -52,7 +52,7 @@ const rehydrateNamesFromContent = (sheet: Sheet, id: string, content: string) =>
 };
 
 const rehydrateSheetFromTag = (sheet: Sheet, style: HTMLStyleElement) => {
-  const parts = (style.innerHTML || '').split(SPLITTER);
+  const parts = (style.textContent || '').split(SPLITTER);
   const rules: string[] = [];
 
   for (let i = 0, l = parts.length; i < l; i++) {