Open Radar

 
Summary:
The hash values for an NSCalendar date and an equal (according to [isEqual:] NSDate

Steps to Reproduce:
	NSDate* date = [NSDate date];
	NSDate* anotherDate = [NSDate dateWithTimeIntervalSinceReferenceDate:
						   [date timeIntervalSinceReferenceDate]];
	NSCalendarDate* calendarDate;
	calendarDate = [NSCalendarDate dateWithTimeIntervalSinceReferenceDate:
					[date timeIntervalSinceReferenceDate]];
	STAssertTrue([date isEqual:anotherDate], 
				 @"isEqual between NSDate and NSDate"); // OK
	STAssertEquals([date hash], [anotherDate hash], 
				   @"equal hash value for NSDate and NSDate"); // OK
	STAssertTrue([date isEqual:calendarDate], 
				 @"isEqual between NSDate and NSCalendarDate"); // OK
	STAssertEquals([date hash], [calendarDate hash], 
				   @"equal hash value for NSDate and NSCalendarDate"); // FAILS

Expected Results:
From the NSObject documentation of hash:
"If two objects are equal (as determined by the isEqual: method), they must have the same hash value. This last point is particularly important if you define hash in a subclass and intend to put instances of that subclass into a collection."

Actual Results:
hash value differs for objects that are equal as determined by isEqual:

Regression:

Notes:
This is extra serious because the Calendar Store framework sometimes returns NSCalendarDates and sometimes NSDates (when making an event occurrence detached).