[WRONG BRANCH] fix: tolerate incompatible Codex history schemas

src/codex/history-provider.ts

@@ -519,6 +519,25 @@ function ejectRemainingOpencodexHistory(db: Database): { rows: number; files: nu
   return { rows: rows.length, files };
 }
 
+function hasCompatibleHistorySchema(stateDbPath: string): boolean {
+  try {
+    const db = new Database(stateDbPath, { readonly: true });
+    try {
+      db.query(`
+        SELECT id, rollout_path, model_provider, source, has_user_event, first_user_message
+        FROM threads
+        LIMIT 0
+      `).all();
+      return true;
+    } finally {
+      db.close();
+    }
+  } catch (error) {
+    if (isRecoverableHistoryError(error)) throw error;
+    return false;
+  }
+}
+
 export function classifyRecoverableHistoryError(error: unknown): CodexHistoryFailureReason | null {
   const code = typeof error === "object" && error && "code" in error ? String((error as { code?: unknown }).code) : "";
   const message = error instanceof Error ? error.message.toLowerCase() : String(error).toLowerCase();
@@ -681,6 +700,10 @@ function restoreCodexHistoryProvider(stateDbPath: string, backupPath: string): C
   const manifest = readBackup(backupPath, stateDbPath);
   const entries = Object.values(manifest.entries);
 
+  // With no manifest there is nothing to restore unless this is a legacy opencodex DB.
+  // Older, empty, or corrupt Codex databases may not have the history schema at all.
+  if (entries.length === 0 && !hasCompatibleHistorySchema(stateDbPath)) return { rows: 0, files: 0 };
+
   const db = openStateDb(stateDbPath);
   try {
     if (entries.length === 0) {

tests/codex-history-provider.test.ts

@@ -267,6 +267,29 @@ describe("Codex history provider sync", () => {
     expect(existsSync(backupPath)).toBe(false);
   });
 
+  test.each([
+    ["no threads table", "CREATE TABLE metadata (key TEXT PRIMARY KEY)"],
+    ["no first_user_message column", "CREATE TABLE threads (id TEXT, rollout_path TEXT, model_provider TEXT, source TEXT, has_user_event INTEGER)"],
+  ])("no-backup restore ignores an incompatible state DB with %s", (_case, schema) => {
+    const dir = join(tmpdir(), `ocx-incompatible-${process.pid}-${Date.now()}-${Math.random().toString(16).slice(2)}`);
+    mkdirSync(dir, { recursive: true });
+    const dbPath = join(dir, "state_5.sqlite");
+    const db = new Database(dbPath);
+    db.run(schema);
+    db.close();
+
+    expect(syncCodexHistoryProvider("openai", dbPath, join(dir, "missing-backup.json"))).toEqual({ rows: 0, files: 0 });
+  });
+
+  test("no-backup restore ignores a corrupt state DB", () => {
+    const dir = join(tmpdir(), `ocx-corrupt-${process.pid}-${Date.now()}-${Math.random().toString(16).slice(2)}`);
+    mkdirSync(dir, { recursive: true });
+    const dbPath = join(dir, "state_5.sqlite");
+    writeFileSync(dbPath, "not a sqlite database");
+
+    expect(syncCodexHistoryProvider("openai", dbPath, join(dir, "missing-backup.json"))).toEqual({ rows: 0, files: 0 });
+  });
+
   test("explicitly recovers legacy opencodex user rows to openai", () => {
     const { dbPath, execRollout, legacyRollout } = makeFixture({ includeExec: true, includeLegacy: true });