crash at WebCore::FrameView::contentsSizeRespectingOverflow

Hi,

We are also seeing this crash in production on iOS9. We have just had one instance on iOS9 but have no clue as to the steps to reproduce.

Hi, does your app do something similar to mine?

What kind of urls would you have been loading? Is your app only loading a few? Do you instantiate new webviews?

I have made a small test app that does the thing that seemed to be crashing our app:

Implement shouldStartLoadWithRequest to return NO for a request

Load and push a new ViewController with a UIWebView on it and send the request to that controller

Load the passed in url in the webview on that controller.

But it only fails when we load urls from our site into the new view. I have tried with a bunch of random urls but have not found any that fail. Also of note is that just repeatedly loading a url into a webview does not cause the problem. I can only make it happen if I create the new webview just before making the request.

We did remove one tracking script from our site and the failure rate went down from 1 in 10 or 20. To somewhere between 1 in 100 and 1 in 500. Though I have now seen the test app happily load the new webview and url over 1000 times. This is a decent heisenbug.

This is a very tricky one and if I had another failing example that would possibly be helpful.

We are getting exactly the same crash from iOS9 (9.0, 9.0.1, 9.1 beta) users. We are presenting modally a view controller which has a UIWebView inside. We call `loadRequest:` from `viewDidLoad:`, but I've also tried to load request from `viewDidAppear`. I can reproduce the crash when I'm quickly presenting and dismissing this view controller multiple times. Sometimes during running this test I'm waiting a little bit for the web page's content to actually load. Then dismiss and present again.

I have also posted here: https://bugs.webkit.org/show_bug.cgi?id=149495 and opened a bug with apple, and contacted DTS.

From feedback in the bugzilla report it does seem like it might be associated with destroying the UIWebView. I guess we have to wait to see how long a fix takes to filter though.

In the mean time I think I am going to change our app to cache the one instance of the second view controller and just re-use it rather than creating a new one each time.

Thanks for investigating this! Please keep us updated about this issue. We are going to ignore this for now.

We are also getting lots of crash reports for one of our apps in `WebCore::FrameView::contentsSizeRespectingOverflow()`.

I was not able to reproduce it. Hope it will be fixed soon in an iOS update.

Try to change a setting in WebView xib.

Scaling -> Scales Page To Fit Unchecked..

NO is already the default value of UIWebView.scalesPageToFit

Just a quick update. I have had a (pretty poor) response to my DTS ticket. Basically: "engineering is investigating" and "as beta releases become available [...] test your issue to see if it has been addressed"

So. Keep hoping that we fix it in a point release.

I am experiencing the same problem, iOS 9, swift, UIWebview presented modally. An assynchronous service is called in ViewDidAppear, the webview is loaded based on the response to this service. Crash is intermittent on the simulator...the stack trace looks the same as yours. There was one crash reported on a device which may be the same but have not obtained crash logs to confirm.

If there is any way I can help to bump up the severity of the DTS ticket based please let me know.

This backtrace has a look of one that a fix has gone into iOS 9.1 beta 4. It would be great to hear if folks reporting this issue can try it on beta 4 and see if it still happens there.

What you need to do to influence apple to spend time on this issue is log your own radar at bugreporter.apple.com - it will get marked as a duplicate, but they use the number of duplicates to rank bugs.

Apparently apple engineering are already looking into it, but another bug report can't hurt.

It may have been "fixed" by beta 4... My test code no longer crashes. The same code does however gets "Terminated due to memory issue" after about 800 or so page loads.

If there was something put in to cache the current viewport renderer, then perhaps it is not being released again?

I have a problem about UIWebView ,Seek for Helping

https://forums.developer.apple.com/message/316963#316963

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