handle external overwrites of adoptedStyleSheets

Author: tophf

content/style-injector.js

@@ -24,12 +24,12 @@ window.StyleInjector = window.INJECTED === 1 ? window.StyleInjector : ({
   const docRewriteObserver = RewriteObserver(updateRoot);
   const docRootObserver = RootObserver(restoreOrder);
   const toSafeChar = c => String.fromCharCode(0xFF00 + c.charCodeAt(0) - 0x20);
-  const getAss = () => Object.isExtensible(ass) ? ass : ass.slice(); // eslint-disable-line no-use-before-define
   /** @type {InjectedStyle[]} */
   const list = [];
   /** @type {Map<number,InjectedStyle>} */
   const table = new Map();
-  let /** @type {CSSStyleSheet[]} */ass;
+  let /** @type {CSSStyleSheet[]} */ ass; // frozen array in old Chrome, the ref changes
+  let /** @type {CSSStyleSheet[]} */ assV2; // mutable array, the ref doesn't change
   let root = document.documentElement;
   let isEnabled = true;
   let isTransitionPatched = chrome.app && CSS.supports('accent-color', 'red'); // Chrome 93
@@ -87,13 +87,13 @@ window.StyleInjector = window.INJECTED === 1 ? window.StyleInjector : ({
 
   function addElement(el, before) {
     if (ass) {
-      const sheets = getAss();
+      const sheets = assV2 || wrappedDoc[kAss];
       let i = sheets.indexOf(el);
       if (i >= 0) el = sheets.splice(i, 1)[0];
       i = before ? sheets.indexOf(before) : -1;
       if (i >= 0) sheets.splice(i, 0, el);
       else sheets.push(el);
-      if (sheets !== ass) wrappedDoc[kAss] = sheets;
+      if (!assV2) wrappedDoc[kAss] = sheets;
     } else {
       updateRoot().insertBefore(el, before);
     }
@@ -112,11 +112,11 @@ window.StyleInjector = window.INJECTED === 1 ? window.StyleInjector : ({
     if (el.remove) {
       el.remove();
     } else if (ass) {
-      const sheets = getAss();
+      const sheets = assV2 || wrappedDoc[kAss];
       const i = sheets.indexOf(el);
       if (i >= 0) {
         sheets.splice(i, 1);
-        if (sheets !== ass) wrappedDoc[kAss] = sheets;
+        if (!assV2) wrappedDoc[kAss] = sheets;
       }
     }
   }
@@ -129,9 +129,9 @@ window.StyleInjector = window.INJECTED === 1 ? window.StyleInjector : ({
 
   function replaceAss(readd) {
     const elems = list.map(s => s.el);
-    const res = ass.filter(arrItemNotIn, new Set(elems));
+    const res = (assV2 || wrappedDoc[kAss]).filter(arrItemNotIn, new Set(elems));
     if (readd) res.push(...elems);
-    ass = wrappedDoc[kAss] = res;
+    wrappedDoc[kAss] = res;
   }
 
   function applyStyles(isReplace, {cfg, sections}) {
@@ -203,7 +203,7 @@ window.StyleInjector = window.INJECTED === 1 ? window.StyleInjector : ({
       id = MEDIA + id;
       el = new CSSStyleSheet({media: id});
       setTextAndName(el, style);
-      for (const {media: m} of ass) if (m.mediaText === id) m.mediaText += '-old';
+      for (const {media: m} of assV2 || wrappedDoc[kAss]) if (m.mediaText === id) m.mediaText += '-old';
       return el;
     }
     if (!creationDoc && (el = initCreationDoc(style))) {
@@ -296,9 +296,9 @@ window.StyleInjector = window.INJECTED === 1 ? window.StyleInjector : ({
           if (ok) return;
         } catch (err) {}
       }
-      if (retry && ffCsp) { // ffCsp bug got fixed
+      if (retry && ffCsp && (ass = wrappedDoc[kAss])) { // ffCsp bug got fixed
         console.debug('Stylus switched to document.adoptedStyleSheets due to a strict CSP of the page');
-        ass = wrappedDoc[kAss];
+        assV2 = Object.isExtensible(ass) && ass;
         return createStyle(style);
       }
       creationDoc = document;
@@ -319,6 +319,7 @@ window.StyleInjector = window.INJECTED === 1 ? window.StyleInjector : ({
     if (!el) {
       bad = false;
     } else if (ass) {
+      if (!assV2) ass = wrappedDoc[kAss];
       for (let i = ass.length - list.length; i < ass.length; i++) {
         if (i < 0 || ass[i] !== list[i].el) {
           bad = true;
@@ -363,6 +364,7 @@ window.StyleInjector = window.INJECTED === 1 ? window.StyleInjector : ({
     if (!ass !== !cfg.ass) {
       removeAllElements();
       ass = ass ? null : wrappedDoc[kAss];
+      assV2 = ass && Object.isExtensible(ass) && ass;
       for (const s of list) s.el = createStyle(s);
       addAllElements();
     }