I’m experiencing multiple crashes where it appears that a native iOS method is calling functions from a third-party library. Here’s an example:
Thread: Unknown Name (Crashed)
0 libsystem_kernel.dylib 0x33222350 __pthread_kill + 8 + 8
1 libsystem_c.dylib 0x3500f973 abort + 95 + 94
2 libsystem_c.dylib 0x34ff04d1 basename + 1
3 FireChat 0x00036489 -[OTOverlayButton drawRect:] + 1
4 Foundation 0x37a4a5a9 -[NSDictionary(NSKeyValueCoding) valueForKey:] + 33 + 32
5 FireChat 0x709d -[NetworkModel getUserForUid:] (NetworkModel.m:150)
6 FireChat 0x0001c42f -[OpenTokController session:didReceiveStream:] (OpenTokController.m:258)
7 libdispatch.dylib 0x32da011f _dispatch_call_block_and_release + 11 + 10
8 libdispatch.dylib 0x32d9f4b7 _dispatch_client_callout + 23 + 22
9 libdispatch.dylib 0x32da41bd _dispatch_main_queue_callback_4CF$VARIANT$mp + 225 + 224
10 CoreFoundation 0x37dbbf3b __CFRunLoopRun + 1291 + 1290
11 CoreFoundation 0x37d2eebd CFRunLoopRunSpecific + 357 + 356
12 CoreFoundation 0x37d2ed49 CFRunLoopRunInMode + 105 + 104
13 GraphicsServices 0x358e22eb GSEventRunModal + 75 + 74
14 UIKit 0x3a1b42f9 UIApplicationMain + 1121 + 1120
15 FireChat 0x43b3 main (main.m:8)
To me, it appears that the [NSDictionary valueForKey:] method is invoking [OTOverlayButton drawRect:] which comes from a third-party library. This shouldn’t be possible — am I reading the crash report wrong?
[OTOverlayButton drawRect:] isn’t called anywhere in my code. Note that the dictionary contains (my) objects which contain pointers to objects from the third-party library.
The library vendor and I are both baffled.
Thanks.
I believe the cause of this crash was memory corruption resulting from calling
performSelector:on a method that returned a struct. See this blog post for more details:Why performSelector is more dangerous than I thought