[iOS] Safari crashes at -[_NSUndoStack popAndInvoke] when trying to undo typing on closed tab

• Component: WebKit2
• Status: RESOLVED FIXED

<rdar://problem/18046692>

Steps to Reproduce:
1. Type something in an input field on a webpage
2. Enter tab view, and close the tab you just typed in
3. Go to another tab
4. Shake to bring up the Undo Typing dialog
5. Tap Undo

Result:
Crash beneath -[_NSUndoStack popAndInvoke].

Created attachment 242834 [details]
Give each WKWebContentView an undo manager

[Anders Carlsson]

Should we do this on OS X as well? Should we do it on the WKWebVIew level instead?

(In reply to comment #2)
> Should we do this on OS X as well?

I don’t know if this bug exists in OS X. The Legacy WebKit implementation of -undoManager differs between iOS and OS X.

> Should we do it on the WKWebVIew level instead?

I don’t know. This change appears to fix the bug as it is.

[Anders Carlsson]

(In reply to comment #3)

> > Should we do it on the WKWebVIew level instead?
> 
> I don’t know. This change appears to fix the bug as it is.

OK. Do you think adding it to the content view instead of the WKWebView could cause any problems for people subclassing WKWebView and overriding -undoManager?

(In reply to comment #4)
> (In reply to comment #3)
> 
> > > Should we do it on the WKWebVIew level instead?
> > 
> > I don’t know. This change appears to fix the bug as it is.
> 
> OK. Do you think adding it to the content view instead of the WKWebView
> could cause any problems for people subclassing WKWebView and overriding
> -undoManager?

Functions in PageClientImplIOS.mm access the WKContentView’s undoManager property directly, so the implementation in the WKWebView subclass won’t be called.

Fixed in <http://trac.webkit.org/r176969>.