Bug 209506 – requestDocumentEditingContext() should bail out if the focused frame does not have a view

• Status: ASSIGNED
• Component: WebKit Misc.

[Daniel Bates]

requestDocumentEditingContext() performs a layout, which can do anything, including document destruction. Ensure that the focused frame has a view before computing the editing context.

[Radar WebKit Bug Importer]

<rdar://problem/60843660>

[Daniel Bates]

Created attachment 394419 [details]
Patch

[Darin Adler]

Comment on attachment 394419 [details]
Patch

Why no test case?

[Daniel Bates]

(In reply to Darin Adler from comment #3)
> Comment on attachment 394419 [details]
> Patch
> 
> Why no test case?

It is hard to write one.

I don't even know how to write such a test. I mean, here's what I need to do:

1. Write a test that will run JavaScript on layout (so, probably need a resize observer) that performs a synchronous navigation.

2. Write an API test that loads that page, get the page into a state where layout is needed, but **not** performed, then call -requestDocumentContext: (again, hoping that layout timer has not run before message gets to web process; otherwise, need to disable that).

Then -requestDocumentContext will message to requestDocumentEditingContext(), which will update layout => triggers navigation => view destroyed and the test will crash without the patch and not crash with it.

[Daniel Bates]

If there is an easier way to write a test I am all ears

[Darin Adler]

That sounds like the right way to write the test. We should really write it. Otherwise we are just making code changes and crossing our fingers.

[Ahmad Saleem]

This patch was modifying:

https://searchfox.org/wubkat/rev/711120e7edec012527620d07bf63d85713a180fd/Source/WebKit/WebProcess/WebPage/ios/WebPageIOS.mm#4935

Which is:



    RefPtr frame = m_page->checkedFocusController()->focusedOrMainFrame();
    if (!frame)
        return completionHandler({ });

__

So I think 275171@main addressed this in bug 269761 and rdar://116201648.

@Alex - above commit was from your side, do you think we need to do anything more here or we can tag this as 'Duplicate' to above bug?