1207179 - Reproducible crash when swiping back or forward

Status: RESOLVED FIXED

(Firefox for iOS :: General, defect)

Description

[Karen Rudnitski [:kar]]

Version 1.1 (1102) on my iPhone 6 running 8.4.1

I go to a website (like m.bbc.co.uk/news/read), tap on an article, then swipe (gesture) to go back (so running my finger left-to-right).

The client crashes.

Fine if I use the back 'arrow' at the bottom. Only happens when I use the gesture.

Comment 1

[Aaron Train [:aaronmt]]

As is tradition, I am unable to reproduce this kar bug. Tried with master and 1.1 on my iPhone 6. I can swipe back fine after reading an article.

Logs/reports?

Comment 2

[Richard Newman [:rnewman]]

I have a bunch of Breakpad crashes. Let me see if I can find them on the server.

Comment 3

[Richard Newman [:rnewman]]

Reproduced just now.

https://crash-stats.mozilla.com/report/index/c863d1b9-aebf-45a8-beb8-58d6b2150922

Comment 4

[Richard Newman [:rnewman]]

    func webView(webView: WKWebView, didFinishNavigation navigation: WKNavigation!) {
        let tab: Browser! = tabManager[webView]
        tabManager.expireSnackbars()

        if let url = webView.URL where !ErrorPageHelper.isErrorPageURL(url) && !AboutUtils.isAboutHomeURL(url) {
            tab.lastExecutedTime = NSDate.now()

            postLocationChangeNotificationForTab(tab, navigation: navigation)

fatal error: unexpectedly found nil while unwrapping an Optional value

navigation is nil in TabManagerNavDelegate.webView:didFinishNavigation: (and thus in the BVC implementation).

Comment 5

[Richard Newman [:rnewman]]

I managed to repro that swiping *forward*, for the record.

Comment 6

[Richard Newman [:rnewman]]

Attachment: Pull request

Comment 7

[Richard Newman [:rnewman]]

Verified:

2015-09-22 17:02:47.373 [Warning] [BrowserViewController.swift:1517] webView(_:didFinishNavigation:) > Implicitly unwrapped optional navigation was nil.
2015-09-22 17:02:47.375 [Debug] [Profile.swift:212] onLocationChange > Recording visit for http://cariboucases.com/What-Fits-My-Bike/ with type 1.

Comment 8

[Karen Rudnitski [:kar]]

(I groaned when I saw comment 1)

If you want me to grab any of my logs, let me know which ones (and where to find them), unless Richard thinks he is confident his STR is the same bug. 

Aaron - if you go to the telegraph (www.telegraph.co.uk), tap on the first article (surprise, it's about the VW scandal), let it load completely (the progress bar finishes) and then swipe back via gesture. 

Looks like it won't reproduce if the page didn't fully load - could you be doing that?

Happens all the time on the bbc as well. Go to www.bbc.co.uk, tap on the first news article, let it load completely, then swipe back. Crash!

Comment 9

[Emily Toop (:fluffyemily)]

Comment on attachment 8664574 [details] [review]
Pull request

Is this an issue worth raising a radar over? Clearly WKNavigation is not supposed to be nil otherwise Apple wouldn't have specified the WKNavigationDelegate method to force unwrap it, but under certain circumstances it is, and the documentation never states that it should be treated as an optional despite the fact it might be.

I was only able to replicate this on my iOS 8.4 device, never on an iOS9 one so it might be a backward compatibility issue, but that's still a bug IMHO.

Comment 10

[Richard Newman [:rnewman]]

http://openradar.appspot.com/radar?id=5586457989218304

rdar://22820815

Comment 11

[Richard Newman [:rnewman]]

https://github.com/mozilla/firefox-ios/commit/3b5b111bd5476cf328213a3f5cba95589e2d8440