Обработать browser storage ошибки и показывать восстановленную форму (#9)

components/upload-recovery.php

@@ -11,9 +11,9 @@ return <<<'JS'
     let storageInitialized = false;
     const initializeStorage = () => {
         if (storageInitialized) return;
-        // window.open копирует sessionStorage родителя. Новый документ с opener
-        // начинает собственный слот; настоящий Reload этой вкладки сохраняет его.
-        if (window.opener && performance.getEntriesByType('navigation')[0]?.type === 'navigate') {
+        // Дублирование вкладки копирует sessionStorage даже без opener. Новый
+        // заход отвязывает только указатели: IndexedDB исходной вкладки не трогаем.
+        if (performance.getEntriesByType('navigation')[0]?.type !== 'reload') {
             for (const name of Object.keys(sessionStorage)) {
                 if (name.startsWith(prefix)) sessionStorage.removeItem(name);
             }
@@ -36,37 +36,54 @@ return <<<'JS'
                 && record.expiresAt === record.createdAt + ttl && record.expiresAt > Date.now()
                 && typeof record.sourceUrl === 'string' && record.sourceUrl.length <= 16384
                 && typeof record.slot === 'string' && json(record.meta) !== undefined
-                && (record.result === null ? (record.blob === null || (record.blob instanceof Blob && record.fileInfo && typeof record.fileInfo.name === 'string' && typeof record.fileInfo.type === 'string' && Number.isFinite(record.fileInfo.lastModified))) : (record.blob === null && record.fileInfo === null && json(record.result) !== undefined));
+                && (record.result === null ? (record.blob === null || ((record.blob instanceof ArrayBuffer || record.blob instanceof Blob) && record.fileInfo && typeof record.fileInfo.name === 'string' && typeof record.fileInfo.type === 'string' && Number.isFinite(record.fileInfo.lastModified))) : (record.blob === null && record.fileInfo === null && json(record.result) !== undefined));
         } catch (_) { return false; }
     };
     const open = () => new Promise((resolve, reject) => {
-        let request;
-        try { request = indexedDB.open('zoomzilla-upload-recovery', 1); } catch (error) { reject(error); return; }
-        let abandoned = false;
+        let request, settled = false;
+        const finish = (error, db) => {
+            if (settled) { if (db) db.close(); return; }
+            settled = true;
+            window.clearTimeout(timer);
+            if (error) reject(error); else resolve(db);
+        };
+        const timer = window.setTimeout(() => finish(failure('open timeout')), 10000);
+        try { request = indexedDB.open('zoomzilla-upload-recovery', 1); } catch (error) { finish(error); return; }
         request.onupgradeneeded = () => request.result.createObjectStore('uploads');
-        request.onerror = () => reject(request.error || failure('open failed'));
-        request.onblocked = () => { abandoned = true; reject(failure('database blocked')); };
+        request.onerror = () => finish(request.error || failure('open failed'));
+        request.onblocked = () => finish(failure('database blocked'));
         request.onsuccess = () => {
-            if (abandoned) { request.result.close(); return; }
             request.result.onversionchange = () => request.result.close();
-            resolve(request.result);
+            finish(null, request.result);
         };
     });
     const transaction = async callback => {
         const db = await open();
         try {
             return await new Promise((resolve, reject) => {
-                let tx, result, cause;
+                let tx, result, settled = false;
                 try { tx = db.transaction('uploads', 'readwrite'); } catch (error) { reject(error); return; }
-                tx.oncomplete = () => resolve(result);
-                tx.onabort = () => reject(cause || tx.error || failure('transaction aborted'));
-                tx.onerror = () => { /* onabort даёт окончательный результат всей транзакции. */ };
-                const fail = error => { cause = error; try { tx.abort(); } catch (_) { reject(error); } };
+                const finish = error => {
+                    if (settled) return;
+                    settled = true;
+                    window.clearTimeout(timer);
+                    if (error) reject(error); else resolve(result);
+                };
+                const fail = error => {
+                    finish(error);
+                    try { tx.abort(); } catch (_) { /* Транзакция могла уже завершиться. */ }
+                };
+                const timer = window.setTimeout(() => fail(failure('transaction timeout')), 10000);
+                tx.oncomplete = () => finish();
+                tx.onabort = () => finish(tx.error || failure('transaction aborted'));
+                // WebKit может дать request/transaction error без последующего abort.
+                tx.onerror = event => fail(event.target.error || tx.error || failure('transaction failed'));
                 try {
                     const store = tx.objectStore('uploads');
                     // Общая уборка сирот/протухших записей, включая давно закрытые вкладки.
                     const cursor = store.openCursor();
                     cursor.onsuccess = () => {
+                        if (settled) return;
                         try {
                             const entry = cursor.result;
                             if (!entry) return;
@@ -113,6 +130,10 @@ return <<<'JS'
                         sessionStorage.removeItem(slot);
                         const metadata = json(meta);
                         if (file !== null && !(file instanceof File)) throw failure('prepared File required');
+                        // ArrayBuffer не зависит от поддержки Blob-файлов в IndexedDB
+                        // (в WebKit её отсутствие проявляется асинхронным UnknownError).
+                        const bytes = file === null ? null : await file.arrayBuffer();
+                        if (generation !== state.generation) throw failure('cancelled');
                         if (key !== undefined && (typeof key !== 'string' || !key || key.length > 200)) throw failure('invalid key');
                         let tab = sessionStorage.getItem(prefix + 'tab');
                         if (!tab) { tab = randomKey(); sessionStorage.setItem(prefix + 'tab', tab); }
@@ -124,7 +145,7 @@ return <<<'JS'
                             const createdAt = resumed ? old.createdAt : Date.now();
                             record = {slot, key: key || randomKey(), createdAt, expiresAt: createdAt + ttl,
                                 sourceUrl: resumed ? old.sourceUrl : location.href, meta: metadata,
-                                blob: file, fileInfo: file === null ? null : {name: file.name, type: file.type, lastModified: file.lastModified}, result: null};
+                                blob: bytes, fileInfo: file === null ? null : {name: file.name, type: file.type, lastModified: file.lastModified}, result: null};
                             if (previous) store.delete(previous);
                             store.put(record, id);
                             done(null);