Crash after backgrounding app from Stats screen

[guarani]

Expected behavior

App shouldn't crash when using Stats.

Actual behavior

I downloaded the app and opened Stats, then I went off to do other things (after backgrounding the app, I think). Then after some minutes, I can back to my phone which was on the Home Screen and I got the alert that the app had crashed.

Here’s the relevant portion of the crash log

Last Exception Backtrace:
0   CoreFoundation                	0x1d3a91e38 __exceptionPreprocess + 164 (NSException.m:202)
1   libobjc.A.dylib               	0x1ccc2f8d8 objc_exception_throw + 60 (objc-exception.mm:356)
2   Foundation                    	0x1ce347a28 -[NSAssertionHandler handleFailureInFunction:file:lineNumber:description:] + 172 (NSException.m:251)
3   UIKitCore                     	0x1d60ab5a0 _UIApplicationDrainManagedAutoreleasePool + 264 (UIApplication+AutoreleasePool.m:171)
4   CoreFoundation                	0x1d3b19d30 __CFRUNLOOP_IS_CALLING_OUT_TO_AN_OBSERVER_CALLBACK_FUNCTION__ + 36 (CFRunLoop.c:1789)
5   CoreFoundation                	0x1d3aa2280 __CFRunLoopDoObservers + 532 (CFRunLoop.c:1902)
6   CoreFoundation                	0x1d3b03c50 __CFRunLoopRun + 1048 (CFRunLoop.c:2981)
7   CoreFoundation                	0x1d3b08eb0 CFRunLoopRunSpecific + 612 (CFRunLoop.c:3418)
8   UIFoundation                  	0x1ddfbab54 -[NSHTMLReader _loadUsingWebKit] + 1436 (NSHTMLReader.m:2633)
9   UIFoundation                  	0x1ddfbb708 -[NSHTMLReader attributedString] + 24 (NSHTMLReader.m:3222)
10  UIFoundation                  	0x1ddf787c4 _NSReadAttributedStringFromURLOrData + 6556 (NSAttributedStringAdditions.m:2741)
11  UIFoundation                  	0x1ddf76db0 -[NSAttributedString(NSAttributedStringUIFoundationAdditions) initWithData:options:documentAttributes:error:] + 148 (NSAttributedStringAdditions.m:1442)
12  Jetpack                       	0x100521d90 @nonobjc NSMutableAttributedString.init(data:options:documentAttributes:) + 144 (:0)
13  Jetpack                       	0x100521680 0x100228000 + 3118720 (NSAttributedString+StyledHTML.swift:23)
14  Jetpack                       	0x100545a44 specialized static StatsTotalInsightsData.makeTotalInsightsGuideText(lastPostInsight:statsSummaryType:) + 700 (StatsTotalInsightsCell.swift:81)
15  Jetpack                       	0x100543368 static StatsTotalInsightsData.makeTotalInsightsGuideText(lastPostInsight:statsSummaryType:) + 12 (:0)
16  Jetpack                       	0x100543368 StatsTotalInsightsCell.rebuildGuideViewIfNeeded() + 104 (StatsTotalInsightsCell.swift:274)
17  Jetpack                       	0x100543368 StatsTotalInsightsCell.traitCollectionDidChange(_:) + 220 (StatsTotalInsightsCell.swift:154)
18  Jetpack                       	0x100543408 @objc StatsTotalInsightsCell.traitCollectionDidChange(_:) + 52 (:0)
  

Steps to reproduce the behavior

1. Install app version 21.6 or above (e.g. from trunk or TestFlight)
2. Log in an open Stats
3. Background the app
4. Notice the app crashes (100% reproducibility)

Tested on iPhone 11, iOS 16.3, JPiOS 21.6.0.1

[staskus]

[staskus]

We call this method when the app is in the background, which causes the crash