sanitize theme names

Author: expikr

src/theme/book.js

@@ -305,7 +305,9 @@ function playground_text(playground, hidden = true) {
         themePopup.querySelectorAll('.theme-selected').forEach(function (el) {
             el.classList.remove('theme-selected');
         });
-        themePopup.querySelector("button#" + get_theme()).classList.add('theme-selected');
+        try {
+            themePopup.querySelector("button#" + get_theme()).classList.add('theme-selected');
+        } catch (e) { }
     }
 
     function hideThemes() {
@@ -360,13 +362,12 @@ function playground_text(playground, hidden = true) {
         }
 
         var previousTheme = get_theme();
-        var themeId = theme.replace(/\W+/g, '_').toLowerCase();
         if (store) {
-            try { localStorage.setItem('mdbook-theme', themeId); } catch (e) { }
+            try { localStorage.setItem('mdbook-theme', theme); } catch (e) { }
         }
 
-        html.classList.remove(previousTheme);
-        html.classList.add(themeId);
+        html.classList.remove(previousTheme.replace(/\W+/g, '_').toLowerCase());
+        html.classList.add(theme.replace(/\W+/g, '_').toLowerCase());
         updateThemeSelected();
     }
 

src/theme/index.hbs

@@ -85,7 +85,7 @@
             var html = document.querySelector('html');
             html.classList.remove('no-js')
             html.classList.remove('{{ default_theme }}')
-            html.classList.add(theme);
+            html.classList.add(theme.replace(/\W+/g, '_').toLowerCase());
             html.classList.add('js');
         </script>