Crash deallocating MGLMapView after adding a point annotation

[1ec5]

MGLMapView doesn’t explicitly remove all its annotations when it gets deallocated, so the dangling KVO observations on the point annotations’ coordinate key paths cause a reliable crash. This regression was introduced in #3835. Here’s an example stack trace:

2016-04-22 12:37:39.870 Mapbox GL[71509:10483627] Ignoring exception raised in void run_cocoa_block(void *): An instance 0x60800088b950 of class DroppedPinAnnotation was deallocated while key value observers were still registered with it. Current observation info: <NSKeyValueObservationInfo 0x600000446510> (
<NSKeyValueObservance 0x6080000d45f0: Observer: 0x101749f70, Key path: coordinate, Options: <New: NO, Old: NO, Prior: NO> Context: 0x0, Property: 0x60800024b880>
)
2016-04-22 12:37:39.878 Mapbox GL[71509:10483627] An uncaught exception was raised
2016-04-22 12:37:39.878 Mapbox GL[71509:10483627] An instance 0x600000097f70 of class DroppedPinAnnotation was deallocated while key value observers were still registered with it. Current observation info: <NSKeyValueObservationInfo 0x608000441a10> (
<NSKeyValueObservance 0x6000000dfcd0: Observer: 0x101749f70, Key path: coordinate, Options: <New: NO, Old: NO, Prior: NO> Context: 0x1, Property: 0x60800024b880>
)
2016-04-22 12:37:39.878 Mapbox GL[71509:10483627] (
    0   CoreFoundation                      0x00007fff902e64f2 __exceptionPreprocess + 178
    1   libobjc.A.dylib                     0x00007fff9534af7e objc_exception_throw + 48
    2   CoreFoundation                      0x00007fff9034d4bd +[NSException raise:format:] + 205
    3   Foundation                          0x00007fff94c37f00 NSKVODeallocate + 294
    4   AppKit                              0x00007fff889c82a6 -[NSViewController dealloc] + 279
    5   AppKit                              0x00007fff88732aad -[NSViewController release] + 133
    6   AppKit                              0x00007fff887f6579 -[NSAutounbinder dealloc] + 51
    7   libobjc.A.dylib                     0x00007fff95340b3b _ZN12_GLOBAL__N_119AutoreleasePoolPage3popEPv + 477
    8   CoreFoundation                      0x00007fff90219c12 _CFAutoreleasePoolPop + 50
    9   AppKit                              0x00007fff8888011d __42-[NSPersistentUIManager acquireDirtyState]_block_invoke + 77
    10  libdispatch.dylib                   0x0000000100d03cc5 _dispatch_client_callout + 8
    11  libdispatch.dylib                   0x0000000100d16ba6 _dispatch_source_latch_and_call + 3387
    12  libdispatch.dylib                   0x0000000100d08cd8 _dispatch_source_invoke + 978
    13  libdispatch.dylib                   0x0000000100d1b012 _dispatch_main_queue_callback_4CF + 1153
    14  CoreFoundation                      0x00007fff9029b9e9 __CFRUNLOOP_IS_SERVICING_THE_MAIN_DISPATCH_QUEUE__ + 9
    15  CoreFoundation                      0x00007fff9025a8dd __CFRunLoopRun + 1949
    16  CoreFoundation                      0x00007fff90259ed8 CFRunLoopRunSpecific + 296
    17  HIToolbox                           0x00007fff975d8935 RunCurrentEventLoopInMode + 235
    18  HIToolbox                           0x00007fff975d876f ReceiveNextEventCommon + 432
    19  HIToolbox                           0x00007fff975d85af _BlockUntilNextEventMatchingListInModeWithFilter + 71
    20  AppKit                              0x00007fff886e8efa _DPSNextEvent + 1067
    21  AppKit                              0x00007fff886e832a -[NSApplication _nextEventMatchingEventMask:untilDate:inMode:dequeue:] + 454
    22  AppKit                              0x00007fff886dce84 -[NSApplication run] + 682
    23  AppKit                              0x00007fff886a646c NSApplicationMain + 1176
    24  Mapbox GL                           0x00000001000098a2 main + 34
    25  libdyld.dylib                       0x00007fff91a205ad start + 1
)
2016-04-22 12:37:39.878 Mapbox GL[71509:10483627] *** Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'An instance 0x600000097f70 of class DroppedPinAnnotation was deallocated while key value observers were still registered with it. Current observation info: <NSKeyValueObservationInfo 0x608000441a10> (
<NSKeyValueObservance 0x6000000dfcd0: Observer: 0x101749f70, Key path: coordinate, Options: <New: NO, Old: NO, Prior: NO> Context: 0x1, Property: 0x60800024b880>
)'
*** First throw call stack:
(
    0   CoreFoundation                      0x00007fff902e64f2 __exceptionPreprocess + 178
    1   libobjc.A.dylib                     0x00007fff9534af7e objc_exception_throw + 48
    2   CoreFoundation                      0x00007fff9034d4bd +[NSException raise:format:] + 205
    3   Foundation                          0x00007fff94c37f00 NSKVODeallocate + 294
    4   AppKit                              0x00007fff889c82a6 -[NSViewController dealloc] + 279
    5   AppKit                              0x00007fff88732aad -[NSViewController release] + 133
    6   AppKit                              0x00007fff887f6579 -[NSAutounbinder dealloc] + 51
    7   libobjc.A.dylib                     0x00007fff95340b3b _ZN12_GLOBAL__N_119AutoreleasePoolPage3popEPv + 477
    8   CoreFoundation                      0x00007fff90219c12 _CFAutoreleasePoolPop + 50
    9   AppKit                              0x00007fff8888011d __42-[NSPersistentUIManager acquireDirtyState]_block_invoke + 77
    10  libdispatch.dylib                   0x0000000100d03cc5 _dispatch_client_callout + 8
    11  libdispatch.dylib                   0x0000000100d16ba6 _dispatch_source_latch_and_call + 3387
    12  libdispatch.dylib                   0x0000000100d08cd8 _dispatch_source_invoke + 978
    13  libdispatch.dylib                   0x0000000100d1b012 _dispatch_main_queue_callback_4CF + 1153
    14  CoreFoundation                      0x00007fff9029b9e9 __CFRUNLOOP_IS_SERVICING_THE_MAIN_DISPATCH_QUEUE__ + 9
    15  CoreFoundation                      0x00007fff9025a8dd __CFRunLoopRun + 1949
    16  CoreFoundation                      0x00007fff90259ed8 CFRunLoopRunSpecific + 296
    17  HIToolbox                           0x00007fff975d8935 RunCurrentEventLoopInMode + 235
    18  HIToolbox                           0x00007fff975d876f ReceiveNextEventCommon + 432
    19  HIToolbox                           0x00007fff975d85af _BlockUntilNextEventMatchingListInModeWithFilter + 71
    20  AppKit                              0x00007fff886e8efa _DPSNextEvent + 1067
    21  AppKit                              0x00007fff886e832a -[NSApplication _nextEventMatchingEventMask:untilDate:inMode:dequeue:] + 454
    22  AppKit                              0x00007fff886dce84 -[NSApplication run] + 682
    23  AppKit                              0x00007fff886a646c NSApplicationMain + 1176
    24  Mapbox GL                           0x00000001000098a2 main + 34
    25  libdyld.dylib                       0x00007fff91a205ad start + 1
)
libc++abi.dylib: terminating with uncaught exception of type NSException
(lldb)