The iPhone rotation crash: taming WebKit's GPU 41506d3

A field report from an iPhone: load the site, rotate as instructed, game crashed. We can't reproduce WebKit in the lab, but the failure shape is a known iOS classic — rotating the device kills or starves the WebGL context, and every iOS generation has its own flavor of it (the canvas-resize memory leak of iOS 14, the context-loss waves of 16.7/17/18). Our code made it worse in two ways: it resized the GL canvas on every resize event — and iOS fires a storm of them mid-rotation with stale geometry — and it had no handler for the context actually dying, so the canvas just went black and stayed dead. From the pilot's seat: crashed.

Two fixes, both verified on the virtual device by forcibly killing the context with the WEBGL_lose_context extension. One: resizing is now debounced and rotation-safe — the geometry storm settles for 180ms (450ms after an orientation change, iOS lands its final dimensions late) before a single canvas re-allocation, degenerate zero-size frames are skipped, and the camera aspect is clamped so a NaN can never poison the projection matrix. Two: a proper context-loss handler — the browser is asked to restore, a GRAPHICS RESET — RECOVERING banner (above) keeps the pilot informed, and if the GPU doesn't come back within four seconds the page reloads itself cleanly instead of sitting dead. Full touch gate re-run after the surgery: 41/41. If you were the pilot who hit this — thanks for the report, and wheels up.