Rekeying or just password change?

Hi,
Let's say that - at some point of time a password repository is stolen and =
the master password is either known or cracked.- to combat this, master pas=
sword is changed

Will the master password change the internal keying, e.g. future versions o=
f the same repository aren't decrypted?

I can think of a few ways this could be implemented,
MASTER_KEY =3D hash(MASTER_PASSWORD).In this implementation, master key wil=
l change if MASTER_PASSWORD change.

MASTER_KEY =3D noise xor hash(MASTER_PASSWORD).In this implementation maste=
r key could remain same upon password change (i.e. could be vulnerable)

So, ... how is it? is rekeying implemented to combat "old version stolen an=
d cracked" scenarios?
 		 	   		  =

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