Open Radar

 
Summary:
I have a category on NSDictionary which creates a new dictionary of the same class using `[[self class] dictionaryWithDictionary:obj]`.  This works fine for mutable dictionaries or dictionaries containing at least one object but dictionaries of zero objects have started crashing in iOS9 saying that __NSDictionary0 doesn't implement -[initWithObjects:forKeys:count:]

Steps to Reproduce:
Run the following code or the attached project:

    id md = [NSMutableDictionary dictionary];
    id d1 = @{@"foo": @"bar"};
    id d0 = @{};
    [[md class] dictionaryWithDictionary:md]; // OK
    [[d1 class] dictionaryWithDictionary:d1]; // OK
    [[d0 class] dictionaryWithDictionary:d0]; // Crash

Expected Results:
The third method call should return a new immutable dictionary, basically:

- initWithObjects:objs forKeys:keys count:count
{
    return [[NSDictionary alloc] initWithObjects:objs forKeys:keys count:count];
}

Actual Results:
App crashes.

Version:
iOS 9 beta 2 and 3, public beta

Notes:


Configuration:
iOS simulator, all devices