Handle existing user has no idp

[quangtruongnb]

When the user enters an existing email and it has no idp, UserModel must be set to context for password form. And if email does not exist and email domain is not configured i think the "user doesn't exist message" should be displayed.

[sventorben]

@quangtruongnb can you please describe the overall behavior you would like to achieve with that? What are the requirements to request such changes?
If you just want username&password form as a fallback, you can just add it as an alternative authenticator.

[quangtruongnb]

@sventorben for normal user, hidp will redirect to their corresponding idp or use user/password form as expected but i think some cases can improve UX:

No.	Input	account already exists	has corresponding domain	Expect	Actual
1	[email protected]	yes	no	user enters their password and can't change username using password form	Error: Invalid username or password.
2	[email protected]	no	no	show error message "user doesn't exist message"	show user/password form