Calendar crashes when minimumDate & maximumDate is set

[snamrata007]

I am using xcode 8.2 and ios 10.1 .

*** Assertion failure in -[UICollectionViewData validateLayoutInRect:], /BuildRoot/Library/Caches/com.apple.xbs/Sources/UIKit_Sim/UIKit-3600.6.21/UICollectionViewData.m:433
2017-02-02 12:01:42.310 DemoCalendar[788:16847] *** Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'UICollectionView received layout attributes for a cell with an index path that does not exist: <NSIndexPath: 0xc000000000000716> {length = 2, path = 7 - 0}'

[krezzoid]

seems like this issue appears only if minimumDate is equal to current date:

    public func minimumDate(for calendar: FSCalendar) -> Date {
        return Date() // crash!
    }
    
    public func maximumDate(for calendar: FSCalendar) -> Date {
        return Date().addDays(365)
    }

[nooralibutt]

@krezzoid I tried your solution. Somehow it worked on some random dates but If I set minimum date two days earlier than current date it still crashes and even 3 days or 4 days. but if I try 7 days before current day it works.

[vibeinging]

复现了这个bug.
2017-02-13 10:32:13.672 FitFile[2198:56208] *** Assertion failure in -[UICollectionViewData validateLayoutInRect:], /BuildRoot/Library/Caches/com.apple.xbs/Sources/UIKit_Sim/UIKit-3600.6.21/UICollectionViewData.m:433
在iPhone上,设置minimumDate和maximumDate都没有问题
但是iPad上,设置这两个必现crashes.

[WenchaoD]

Can't reproduce this in demo project. Can anyone provide a demo with latest code in master?

[markj]

I have this problem too. Although in my case the minimum date is set to 3 months ago..
If I set the maximum date to today, it crashes. Changing that to Date.distantFuture it's fine.

[markj]

I still get this problem with the latest master (with #585 merged in).

Strangely the issue occurs when running the iPhone only app on an iPad but not on an iPhone.

[krezzoid]

Strangely the issue occurs when running the iPhone only app on an iPad but not on an iPhone.

for me this always happens with iPhone only app running on iPhone :) latest version of Xcode & simulator

[markj]

I've updated the swift demo app with code similar to what I'm using.
Strangely it doesn't crash in the situation I have when running against iOS 10 but it does show the same problem for iOS 9 running on the iPhone 4s.

https://github.com/markj/FSCalendar/commits/master

To reproduce,

1. Start iPhone 4s sim (9.3)
2. Launch swift demo app
3. Select FSCalendarScope

Boom:

2017-02-13 10:06:51.771 FSCalendarSwiftExample[2951:2320699] *** Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'UICollectionView received layout attributes for a cell with an index path that does not exist: <NSIndexPath: 0x7a0cff00> {length = 2, path = 4 - 0}'
*** First throw call stack:
(
	0   CoreFoundation                      0x00cbd494 __exceptionPreprocess + 180
	1   libobjc.A.dylib                     0x0077ee02 objc_exception_throw + 50
	2   CoreFoundation                      0x00cbd32a +[NSException raise:format:arguments:] + 138
	3   Foundation                          0x003fa322 -[NSAssertionHandler handleFailureInMethod:object:file:lineNumber:description:] + 118
	4   UIKit                               0x02353e55 __45-[UICollectionViewData validateLayoutInRect:]_block_invoke + 1116
	5   UIKit                               0x02352dfb -[UICollectionViewData validateLayoutInRect:] + 1329
	6   UIKit                               0x02355b79 -[UICollectionViewData layoutAttributesForElementsInRect:] + 132
	7   UIKit                               0x022ef237 -[UICollectionView _updateVisibleCellsNow:] + 605
	8   UIKit                               0x022f57df -[UICollectionView layoutSubviews] + 254
	9   UIKit                               0x01a333d4 -[UIView(CALayerDelegate) layoutSublayersOfLayer:] + 810
	10  libobjc.A.dylib                     0x00793059 -[NSObject performSelector:withObject:] + 70
	11  QuartzCore                          0x01829096 -[CALayer layoutSublayers] + 144
	12  QuartzCore                          0x0181c8b6 _ZN2CA5Layer16layout_if_neededEPNS_11TransactionE + 388
	13  QuartzCore                          0x0181c71a _ZN2CA5Layer28layout_and_display_if_neededEPNS_11TransactionE + 26
	14  QuartzCore                          0x0180eee7 _ZN2CA7Context18commit_transactionEPNS_11TransactionE + 317
	15  QuartzCore                          0x01843847 _ZN2CA11Transaction6commitEv + 561
	16  QuartzCore                          0x018450b8 _ZN2CA11Transaction17flush_transactionEv + 50
	17  UIKit                               0x01994f55 _afterCACommitHandler + 197
	18  CoreFoundation                      0x00bcf75e __CFRUNLOOP_IS_CALLING_OUT_TO_AN_OBSERVER_CALLBACK_FUNCTION__ + 30
	19  CoreFoundation                      0x00bcf6be __CFRunLoopDoObservers + 398
	20  CoreFoundation                      0x00bc503c __CFRunLoopRun + 1340
	21  CoreFoundation                      0x00bc4846 CFRunLoopRunSpecific + 470
	22  CoreFoundation                      0x00bc465b CFRunLoopRunInMode + 123
	23  GraphicsServices                    0x05d2a664 GSEventRunModal + 192
	24  GraphicsServices                    0x05d2a4a1 GSEventRun + 104
	25  UIKit                               0x01962eb9 UIApplicationMain + 160
	26  FSCalendarSwiftExample              0x00110cf1 main + 145
	27  libdyld.dylib                       0x002a5a25 start + 1
)

[enfoiro]

We started to have this issue when we upgraded from 2.3.0 -> 2.6.0, we tried with the latest release as well, still the same issue, so we downgraded back to 2.3.0, happening when we have a date selected, plus a min and max date set, can happen when loading the view, or scrolling to change the month.
Strange thing is that I think it's happening only when having a selected date in february, maybe it has to do with the fact that they are less days in this month.
When we have a selected date in a different month, we can't reproduce the bug.

🤞 Hope it'll help.

[WenchaoD]

@markj I reproduced your issue from your forked branch. But this is fixed after I override the FSCalendar folder from development branch. Would you guys like to try again and provide some feedback?

[backofthecup]

Using the development branch worked for me. Thanks! When do you think this might be pushed to the CocoaPod repository?

[markj]

Oh darn it! You are right. Sorry, I didn't see the dev branch - just master was newer than the tag..

I no longer see the issue with the development branch either..

Great stuff! Thanks.

[backofthecup]

There's definitely an issue when the selectDate = minimumDate. The selected date that shows on the calendar is the day before what was specified. I've attached a small project showing this.

CalendarTest.zip

[WenchaoD]

@backofthecup Pushed to Cocoapods. Please try 2.7.2, along with the fix of your last issue.