fix(vscode): keep a pending permission mode when applying it fails

Author: elkaix

apps/vscode/src/runtime/pythinker-runtime.ts

@@ -239,8 +239,13 @@ export class PythinkerRuntime {
   ): Promise<void> {
     const pending = this.pendingPermissionByView.get(webviewId);
     if (pending === undefined) return;
-    this.pendingPermissionByView.delete(webviewId);
     await runtime.setPermissionMode(pending);
+    // Dropped only once it landed, and only if it is still the request in hand:
+    // a failed apply keeps the command for the next attempt, and a command that
+    // arrived during the await outranks the one just applied.
+    if (this.pendingPermissionByView.get(webviewId) === pending) {
+      this.pendingPermissionByView.delete(webviewId);
+    }
   }
 
   private wrapSession(session: Session, permissionMode: PermissionMode): SessionRuntime {

apps/vscode/test/pythinker-runtime.test.ts

@@ -493,6 +493,22 @@ describe("Pythinker runtime (owns shared SDK sessions for Webviews)", () => {
     expect(runtime.pendingPermissionTarget("view-1", "manual").permissionMode).toBe("manual");
   });
 
+  it("keeps a pending permission mode when applying it to the session fails", async () => {
+    const { runtime, sdk } = createRuntime();
+    const boundary = sdk.addSession("saved-1", "/workspace");
+    (boundary.session as { setPermission: (mode: PermissionMode) => Promise<void> }).setPermission =
+      async () => {
+        throw new Error("engine offline");
+      };
+    await runtime.pendingPermissionTarget("view-1", "manual").setPermissionMode("yolo");
+
+    await expect(
+      runtime.openSession(openOptions({ webviewId: "view-1", sessionId: "saved-1" })),
+    ).rejects.toThrow("engine offline");
+
+    expect(runtime.pendingPermissionTarget("view-1", "manual").permissionMode).toBe("yolo");
+  });
+
   it("persists a mode change so the next attach restores it", async () => {
     const { runtime, sdk } = createRuntime();
     const session = sdk.addSession("saved-1", "/workspace", { permission: "manual" });