Open Radar

 
When an NSWindow is closed immediately after allocation, a crash occurs during objc_autoreleasePoolPop when the surrounding autorelease pool is flushed. 

Either of the following will avoid the crash:
1. Set window.releasedWhenClosed = NO;
2. Do not call close.

The following is a full repro: 
@autoreleasepool {
  NSWindow* window = [[NSWindow alloc] init];
  [window close];
}

For convenience, I've posted a project here: https://github.com/cbracken/NSWindowCrash that demonstrates the issue. 


## Expected behaviour
Closing an NSWindow immediately after allocation should succeed.


## Actual behaviour
Closing an NSWindow immediately after allocation, followed by being flushed from the autorelease pool causes a crash with the following stack trace.
Thread 0 Crashed::  Dispatch queue: com.apple.main-thread
0   libobjc.A.dylib               	       0x18d8f7ed8 objc_release + 16
1   libobjc.A.dylib               	       0x18d8ff418 AutoreleasePoolPage::releaseUntil(objc_object**) + 196
2   libobjc.A.dylib               	       0x18d8fbaf0 objc_autoreleasePoolPop + 260
3   NSWindowCrash                 	       0x102213f40 main + 96 (main.m:12)
4   dyld                          	       0x18d945058 start + 2224


## Discussion
While a developer is unlikely to ever intentionally write such code, it may occur in the context of a more complicated app where a window is both allocated and hits some condition that results in immediate close, or in minimal unit tests where a developer allocates a window in order to perform a test (in my case, related to accessibility notifications), and then clean up after itself.

Either way, this probably shouldn't crash, or should be documented in NSWindow close.