# Phase 10 — Robustness & Cleanup

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## Step 10.1 — Proper error handling

- Set `XSetErrorHandler()` to a handler that logs but doesn't crash on
  `BadWindow`, `BadPixmap`, `BadDrawable` (windows can vanish between
  operations).
- Wrap all X calls that reference a window in the handler's
  error-checked scope.
- On fatal errors (`XSetIOErrorHandler`), clean up gracefully.

**Verify:** Rapidly spawn and kill clients (a stress loop script). No
crashes, no X error floods. Clean log output.

---

## Step 10.2 — Clean shutdown

On `SIGINT`/`SIGTERM` or raylib `WindowShouldClose()`:

1. Unredirect all windows (`XCompositeUnredirectSubwindows`).
2. Free all pixmaps, textures, damage objects.
3. Release the overlay (if used later).
4. `XCloseDisplay()`.
5. `CloseWindow()` (raylib).

**Verify:** Killing the WM with Ctrl+C cleanly restores windows in
Xephyr (they become visible via X's normal rendering again). No
orphaned resources.

---

## Step 10.3 — Stress test script

Create `bin/stress-test.sh` that:

1. Starts Xephyr.
2. Starts the WM.
3. Rapidly spawns 20 `xterm` instances.
4. Randomly moves, resizes, and closes them via `xdotool`.
5. Checks that `wmctrl -l` count matches expectations.
6. Screenshots the result.
7. Tears everything down.

**Verify:** No crashes, no hangs, no leaked windows. Screenshot looks
sane.