Bug 299635 – REGRESSION (300338@main): Null pointer crashes in WebFrameInspectorTargetProxy::disconnect()

• Status: RESOLVED
• Resolution: FIXED
• Component: Web Inspector

[Yury Semikhatsky]

We are seing the following crash because of null WebFrameProxy reference in WebFrameInspectorTargetProxy:

[Yury Semikhatsky]

```
    frame #6: 0x000077d74395fb06 libWPEWebKit-2.0.so.1`WebKit::WebFrameInspectorTargetProxy::disconnect() + 486
    frame #7: 0x000077d744749bc3 libWPEWebKit-2.0.so.1`Inspector::InspectorTargetAgent::willDestroyFrontendAndBackend(Inspector::DisconnectReason) + 163
    frame #8: 0x000077d74469251c libWPEWebKit-2.0.so.1`Inspector::AgentRegistry::willDestroyFrontendAndBackend(Inspector::DisconnectReason) + 44
    frame #9: 0x000077d743965cf3 libWPEWebKit-2.0.so.1`WebKit::WebPageInspectorController::disconnectAllFrontends() + 35
    frame #10: 0x000077d743965ab6 libWPEWebKit-2.0.so.1`WebKit::WebPageInspectorController::pageClosed() + 54
    frame #11: 0x000077d743815df3 libWPEWebKit-2.0.so.1`WebKit::WebPageProxy::close() + 803
    frame #12: 0x000077d7439105b1 libWPEWebKit-2.0.so.1`webkitWebViewDispose(_GObject*) + 417
    frame #13: 0x000077d73e460ed1 libgobject-2.0.so.0`g_object_unref + 305
```

It happens when inspected page is being closed after it crashed. In that case `destroyInspectorTarget` is not called here[1] because m_page is already null.


[1] https://github.com/WebKit/WebKit/blob/1dbd421437f8d1929d74ae8bb8381c9e23b64702/Source/WebKit/UIProcess/WebFrameProxy.cpp#L128-L129

[Yury Semikhatsky]

This started happening after https://github.com/WebKit/WebKit/pull/50623.

[Yury Semikhatsky]

Pull request: https://github.com/WebKit/WebKit/pull/51409

[Radar WebKit Bug Importer]

<rdar://problem/161445124>

[Yury Semikhatsky]

Can be easily reproduced with playwright by running `npm run wtest -- tests/library/page-event-crash.spec.ts`, see the tests in  https://github.com/microsoft/playwright/blob/main/tests/library/page-event-crash.spec.ts.

[EWS]

Committed 300724@main (e38da632bbcf): <https://commits.webkit.org/300724@main>

Reviewed commits have been landed. Closing PR #51409 and removing active labels.