Open Radar

 
Summary:
We want users to be able to enter the password after canceling or failed to retrieve password via TouchId.
So we make the text field a first responder while keychain retrieval failed.
However, on iOS 10 the keyboard become invisible but still hittable while the text field becomes first responder.

There are some other people have the same issue:
http://stackoverflow.com/questions/39045675/ios-keyboard-inside-uiremotekeyboardwindow-is-not-shown-when-uitextfield-becom

Steps to Reproduce:
1. Here is our code snippet:
    dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
        NSMutableDictionary *query = [self.class sacDictionary:key];
        if (prompt) {
            query[(__bridge id)kSecReturnData] = @YES;
            query[(__bridge id)kSecUseOperationPrompt] = prompt;
        }
        CFTypeRef dataTypeRef = NULL;
        OSStatus status = SecItemCopyMatching((__bridge CFDictionaryRef)[query copy], &dataTypeRef);
        if (status == errSecSuccess) {
            weakSelf.textField.text = (dataTypeRef ? [NSString stringWithUTF8String:[(__bridge_transfer NSData *)dataTypeRef bytes]] : nil);
        } else {
            [weakSelf.textField becomeFirstResponder];
        }
    });
2. click cancel after TouchId dialog popped
3. hit the area of keyboard

Expected Results:
The keyboard should appear.

Actual Results:
The keyboard is blank but hittable.

Version:
10.0.1 (14A403)