1354938 - Crash in AppDelegate.applicationDidEnterBackground(UIApplication) -> ()

Status: RESOLVED FIXED

(Firefox for iOS :: General, defect)

Description

[Stefan Arentz | :st3fan | ⏰ EST | he/him]

Stack trace:

0   Client                              0x00000001001e508c specialized AppDelegate.applicationDidEnterBackground(UIApplication) -> () (AppDelegate.swift:376)
1   Client                              0x00000001001dd600 @objc AppDelegate.applicationDidEnterBackground(UIApplication) -> () (AppDelegate.swift:0)
2   UIKit                               0x00000001877b7984 __47-[UIApplication _applicationDidEnterBackground]_block_invoke + 184
3   UIKit                               0x0000000187893638 +[UIViewController _performWithoutDeferringTransitions:] + 128
4   UIKit                               0x00000001877b7878 -[UIApplication _applicationDidEnterBackground] + 100
5   UIKit                               0x00000001877b7e00 -[UIApplication _handleApplicationDeactivationWithScene:shouldForceExit:transitionContext:completion:] + 692
6   UIKit                               0x00000001877af708 -[UIApplication workspaceShouldExit:withTransitionContext:] + 320
7   FrontBoardServices                  0x000000018324b92c __FBSSERIALQUEUE_IS_CALLING_OUT_TO_A_BLOCK__ + 36
8   FrontBoardServices                  0x000000018324b798 -[FBSSerialQueue _performNext] + 176
9   FrontBoardServices                  0x000000018324bb40 -[FBSSerialQueue _performNextFromRunLoopSource] + 56
10  CoreFoundation                      0x0000000181622b5c __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__ + 24
11  CoreFoundation                      0x00000001816224a4 __CFRunLoopDoSources0 + 524
12  CoreFoundation                      0x00000001816200a4 __CFRunLoopRun + 804
13  CoreFoundation                      0x000000018154e2b8 CFRunLoopRunSpecific + 444
14  UIKit                               0x00000001875957b0 -[UIApplication _run] + 608
15  UIKit                               0x0000000187590534 UIApplicationMain + 208
16  Client                              0x00000001000a2994 main (main.swift:0)
17  libdyld.dylib                       0x00000001805315b8 start + 4

The code at AppDelegate.swift:376 mentions it is a weird workaround for a bug. Unfortunately not a Bugzilla bug number but I think it is fair to assume this workaround has been with us for a long time.

A lot has changed in our app and in iOS/WebKit, so I would like to suggest that we simply remove this workaround code.

Comment 1

[Stefan Arentz | :st3fan | ⏰ EST | he/him]

Attachment: PR https://github.com/mozilla-mobile/firefox-ios/pull/2613

Removed an old workaround that is appearing in our top 10 crashes.

Comment 2

[Farhan Patel [:farhan]]

Its been around for a year. Here is the original bug https://bugzilla.mozilla.org/show_bug.cgi?id=1218827

And the follow up to remove the workaround. https://bugzilla.mozilla.org/show_bug.cgi?id=1247115

There has been 0 movements on the rdar. But I'll use the original bug to see if we can still reproduce this.

Comment 3

[Farhan Patel [:farhan]]

It doesnt crash for me in the simulator. On both 9.0 and 10.0

Comment 4

[Stefan Arentz | :st3fan | ⏰ EST | he/him]

Landed on v7.x and master.