SPMemberDouble Crash

[larryryu]

Getting a crash when syncing changes to double field.
checkout fork:
https://github.com/larryryu/simperium-ios

Steps to reproduce

• Replace "SIMPERIUM_APP_ID", "SIMPERIUM_API_KEY" with appropriate values in AppDelegaae
• Install Final sample Todo App on 2 devices
  (https://github.com/larryryu/simperium-ios/tree/develop/samples/Simpletodo/SimpletodoFinal)
• Create a new Todo item on device A
• Make sure the new entry shows up on device B
• Tap to edit the todo on device A
• Set second textfield value to 2, make sure changes synced.
• Put device A in airplane mode keep device B online
• On device A, clear the second textfield
• On device B change second textfield to 4
• Tap back button on both devices
• Turn off airplane mode on device A so that changes are synced.

Observe that device A crashes. Any attempt to restart the app results in the same crash

Here is the stack trace

Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '*** -[__NSPlaceholderDictionary initWithObjects:forKeys:count:]: attempt to insert nil object from objects[1]'
*** First throw call stack:
(
0 CoreFoundation 0x0000000103ee2e65 __exceptionPreprocess + 165
1 libobjc.A.dylib 0x000000010395bdeb objc_exception_throw + 48
2 CoreFoundation 0x0000000103de58ce -[__NSPlaceholderDictionary initWithObjects:forKeys:count:] + 318
3 CoreFoundation 0x0000000103df7c3b +[NSDictionary dictionaryWithObjects:forKeys:count:] + 59
4 SimpletodoFinal 0x0000000100ea2135 -[SPMemberDouble transform:otherValue:oldValue:error:] + 213
5 SimpletodoFinal 0x0000000100ec43a1 -[SPDiffer transform:diff:oldDiff:oldGhost:error:] + 2049
6 SimpletodoFinal 0x0000000100e8f259 -[SPChangeProcessor _processRemoteModifyWithKey:bucket:threadSafeStorage:change:acknowledged:clientMatches:error:] + 5897
7 SimpletodoFinal 0x0000000100e8d984 __95-[SPChangeProcessor processRemoteModifyWithKey:bucket:change:acknowledged:clientMatches:error:]_block_invoke + 116
8 SimpletodoFinal 0x0000000100e8a781 -[SPCoreDataStorage performSafeBlockAndWait:] + 1105
9 SimpletodoFinal 0x0000000100e8d800 -[SPChangeProcessor processRemoteModifyWithKey:bucket:change:acknowledged:clientMatches:error:] + 608
10 SimpletodoFinal 0x0000000100e91210 -[SPChangeProcessor processRemoteChange:bucket:error:] + 3552
11 SimpletodoFinal 0x0000000100e925d4 -[SPChangeProcessor processRemoteChanges:bucket:successHandler:errorHandler:] + 2244
12 SimpletodoFinal 0x0000000100ee15d8 -[SPWebSocketChannel processBatchChanges:bucket:] + 1656
13 SimpletodoFinal 0x0000000100ee0e37 __49-[SPWebSocketChannel handleRemoteChanges:bucket:]_block_invoke + 535
14 libdispatch.dylib 0x0000000104418e5d _dispatch_call_block_and_release + 12
15 libdispatch.dylib 0x000000010443949b _dispatch_client_callout + 8
16 libdispatch.dylib 0x000000010441f8ec _dispatch_queue_drain + 2215
17 libdispatch.dylib 0x000000010441ee0d _dispatch_queue_invoke + 601
18 libdispatch.dylib 0x0000000104421a56 _dispatch_root_queue_drain + 1420
19 libdispatch.dylib 0x00000001044214c5 _dispatch_worker_thread3 + 111
20 libsystem_pthread.dylib 0x000000010477168f _pthread_wqthread + 1129
21 libsystem_pthread.dylib 0x000000010476f365 start_wqthread + 13
)
libc++abi.dylib: terminating with uncaught exception of type NSException
(lldb)

[jleandroperez]

Hello @larryryu,

Thanks for reporting this one!. I've just pushed a fix to address this scenario. Would it be possible to validate everything works as expected?

Thanks in advance!