[webkit-changes] [WebKit/WebKit] 530a64: Fix crash in WebPageProxy::wheelEventHandlingCompl...

[Simon Fraser]

  Branch: refs/heads/main
  Home:   https://github.com/WebKit/WebKit
  Commit: 530a64fb16571884b79d4e6c7eabbe3defdd4f4d
      https://github.com/WebKit/WebKit/commit/530a64fb16571884b79d4e6c7eabbe3defdd4f4d
  Author: Simon Fraser <simon.fraser at apple.com>
  Date:   2023-07-06 (Thu, 06 Jul 2023)

  Changed paths:
    M Source/WebKit/UIProcess/WebPageProxy.cpp

  Log Message:
  -----------
  Fix crash in WebPageProxy::wheelEventHandlingCompleted()
https://bugs.webkit.org/show_bug.cgi?id=258705
rdar://111445101

Reviewed by Cameron McCormack.

Crash data show crashes in WebPageProxy::wheelEventHandlingCompleted(), and many of these are under WebProcessProxy::shutDown(),
suggesting that we've closed the WebPageProxy. This is indeed possible, since WebPageProxy::sendWheelEvent() sends IPC
with an async reply.

So early return in the reply handler if closed, and also null-check the m_pageClient (which is a WeakPtr).

* Source/WebKit/UIProcess/WebPageProxy.cpp:
(WebKit::WebPageProxy::sendWheelEvent):
(WebKit::WebPageProxy::wheelEventHandlingCompleted):

Canonical link: https://commits.webkit.org/265817@main