[TIMOB-24320] iOS: Removing a TableView with headerView may cause the app to crash

GitHub Issue	n/a
Type	Bug
Priority	Critical
Status	Closed
Resolution	Fixed
Resolution Date	2017-01-26T22:53:59.000+0000
Affected Version/s	n/a
Fix Version/s	Release 6.1.0
Components	iOS
Labels	n/a
Reporter	Shinya Kasatani
Assignee	Hans Knöchel
Created	2017-01-17T15:12:00.000+0000
Updated	2017-10-15T08:31:08.000+0000

Description

I have an app with TableView with headerView or footerView specified. When you add this view into ScrollableView and removing it afterwards, it causes the app to crash with SIGABRT. It happens on both simulator and the device. Here is the crash log:

Exception Type:  EXC_CRASH (SIGABRT)
Exception Codes: 0x0000000000000000, 0x0000000000000000
Exception Note:  EXC_CORPSE_NOTIFY
Termination Reason: Namespace OBJC, Code 0x1
Triggered by Thread:  0

Filtered syslog:
None found

Thread 0 name:  Dispatch queue: com.apple.main-thread
Thread 0 Crashed:
0   libsystem_kernel.dylib        	0x0000000180fd0d74 __abort_with_payload + 8
1   libsystem_kernel.dylib        	0x0000000180fcd480 abort_with_payload_wrapper_internal + 100
2   libsystem_kernel.dylib        	0x0000000180fcd41c abort_with_payload_wrapper_internal + 0
3   libobjc.A.dylib               	0x0000000180a3bed8 _objc_fatalv(unsigned long long, unsigned long long, char const*, char*) + 112
4   libobjc.A.dylib               	0x0000000180a3be30 __objc_error + 0
5   libobjc.A.dylib               	0x0000000180a4ecd4 weak_entry_insert(weak_table_t*, weak_entry_t*) + 0
6   libobjc.A.dylib               	0x0000000180a542a8 objc_storeWeak + 328
7   UIKit                         	0x0000000187f097fc -[UIScrollView setDelegate:] + 336
8   UIKit                         	0x0000000187f357ec -[UITableView setDelegate:] + 368
9   App                          	0x000000010018518c -[TiUITableView tableView] (TiUITableView.m:0)
10  App                          	0x000000010018de88 __34-[TiUITableView proxyDidRelayout:]_block_invoke (TiUITableView.m:1750)
11  libdispatch.dylib             	0x0000000180e8d200 _dispatch_call_block_and_release + 24
12  libdispatch.dylib             	0x0000000180e8d1c0 _dispatch_client_callout + 16
13  libdispatch.dylib             	0x0000000180e91d6c _dispatch_main_queue_callback_4CF + 1000
14  CoreFoundation                	0x0000000181faff2c __CFRUNLOOP_IS_SERVICING_THE_MAIN_DISPATCH_QUEUE__ + 12
15  CoreFoundation                	0x0000000181fadb18 __CFRunLoopRun + 1660
16  CoreFoundation                	0x0000000181edc048 CFRunLoopRunSpecific + 444
17  GraphicsServices              	0x0000000183962198 GSEventRunModal + 180
18  UIKit                         	0x0000000187ec72fc -[UIApplication _run] + 684
19  UIKit                         	0x0000000187ec2034 UIApplicationMain + 208
20  App                          	0x000000010010a4d8 main (main.m:30)
21  libdyld.dylib                 	0x0000000180ec05b8 start + 4

I guess this happens after the TiUITableView is dealloc'ed and the headerViewProxy is still alive at that time. The app doesn't crash when you call [headerViewProxy setProxyObserver:nil] from -[TiUITableView dealloc]. I have tried to create a simple example to describe this problem, but I have not successfully created one that reproduces the issue.

Attachments

File	Date	Size
tableview-fix.patch	2017-01-17T15:10:26.000+0000	445

Comments

Sharif AbuDarda 2017-01-17

Hello, We need a sample code for us to verify the issue to apply a fix. Please provide one sample code that regenerates the issue. Thanks.
Hans Knöchel 2017-01-17

Hey [~kasatani], your proposal looks pretty good so far. either the delegate or the property observer is making problems, so when you nil it, it won't call the delegate and therefore don't crash. Good catch! Do you want to do a PR to the open source project yourself or should we do one? And [~sdarda] is right, we still need a demo-code, so our QE can validate the possible fix. Thx! *EDIT*: This does not happen with Ti.UI.ListView as far as I can see ([gist](https://gist.github.com/hansemannn/5bcf6b1b2fde58da387ca902ae1d5bd2)) *EDIT*: Same with Ti.UI.TableView, not reproducible ([gist](https://gist.github.com/hansemannn/a43b545566d064d308e3d111ddecdc8f))

Hans Knöchel 2017-01-17

PR: https://github.com/appcelerator/titanium_mobile/pull/8758 Test-Case (will not always throw without the fix, but with the fix, it will never):

   var win = Ti.UI.createWindow({
       backgroundColor: '#fff'
   });
   
   var btn = Ti.UI.createButton({
       title: 'Remove',
       top: 20,
       right: 20,
       height: 40,
       backgroundColor: 'black'
   });
   
   var scrollable = Ti.UI.createScrollableView({
       showPagingControl: true,
       pagingControlColor: 'red'
   });
   var list1 = Ti.UI.createTableView({
       backgroundColor: 'red', 
       headerView: Ti.UI.createView({
           height: 50,
           backgroundColor: 'yellow'
       })
   });
   
   var list2 = Ti.UI.createTableView({backgroundColor: 'green'});
   var list3 = Ti.UI.createTableView({backgroundColor: 'blue'});
   
   scrollable.addView(list1);
   scrollable.addView(list2);
   scrollable.addView(list3);
   
   btn.addEventListener('click', function() {
       btn.setEnabled(false);
       
       setInterval(function() {
           scrollable.removeView(list1);
           setTimeout(function() {
               scrollable.addView(list1);
               list1.setHeaderView(Ti.UI.createView({
                   height: 50,
                   backgroundColor: 'green'
               }));
           },1000);
       },1500)
   });
   
   win.add(scrollable);
   win.add(btn);
   win.open();

Note: This test-case will trigger an add/remove loop, so we get more potential cases where it would crash.

Hans Knöchel 2017-01-18

[~kasatani] I added some more changes in https://github.com/appcelerator/titanium_mobile/pull/8758 additional to yours, can you validate that this is this fine?
Shinya Kasatani 2017-01-19

Thanks for creating a PR! I have confirmed that this fixes the problem.
Eric Wieber 2017-01-26

FR passed, using: MacOS 10.12 (16A323) Studio 4.8.1.201612050850 Ti SDK 6.1.0 Appc NPM 4.2.8 Appc CLI 6.1.0 Alloy 1.9.5 Xcode 8.2 (8C38) No crash encountered when adding or removing a tableview with a headerview. Tested using the provided test case (left running for over a minute) and manually adding and removing the views.
Eric Wieber 2017-01-27

Verified in SDK 6.1.0.v20170126150653

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