safeSubarrayWithRange 越界判断bug

[due2signal9]

- (NSArray *)safeSubarrayWithRange:(NSRange)range
{
	if ( 0 == self.count )
		return nil;

	if ( range.location >= self.count )
		return nil;

	if ( range.location + range.length >= self.count )
		return nil;
	
	return [self subarrayWithRange:NSMakeRange(range.location, range.length)];
}

应为

if ( range.location >= self.count )
     return nil;

 if ( range.location + range.length > self.count )
		return nil;
	
	return [self subarrayWithRange:NSMakeRange(range.location, range.length)];