Revert deletion of hydrateSession

src/Lifecycle.ts

@@ -701,6 +701,43 @@ export async function setLoggedIn(credentials: IMatrixClientCreds): Promise<Matr
     return doSetLoggedIn(credentials, true, true);
 }
 
+/**
+ * Hydrates an existing session by using the credentials provided. This will
+ * not clear any local storage, unlike setLoggedIn().
+ *
+ * Stops the existing Matrix client (without clearing its data) and starts a
+ * new one in its place. This additionally starts all other react-sdk services
+ * which use the new Matrix client.
+ *
+ * If the credentials belong to a different user from the session already stored,
+ * the old session will be cleared automatically.
+ *
+ * @param {IMatrixClientCreds} credentials The credentials to use
+ *
+ * @returns {Promise} promise which resolves to the new MatrixClient once it has been started
+ */
+export async function hydrateSession(credentials: IMatrixClientCreds): Promise<MatrixClient> {
+    const oldUserId = MatrixClientPeg.safeGet().getUserId();
+    const oldDeviceId = MatrixClientPeg.safeGet().getDeviceId();
+
+    stopMatrixClient(); // unsets MatrixClientPeg.get()
+    localStorage.removeItem("mx_soft_logout");
+    _isLoggingOut = false;
+
+    const overwrite = credentials.userId !== oldUserId || credentials.deviceId !== oldDeviceId;
+    if (overwrite) {
+        logger.warn("Clearing all data: Old session belongs to a different user/session");
+    }
+
+    if (!credentials.pickleKey && credentials.deviceId !== undefined) {
+        logger.info("Lifecycle#hydrateSession: Pickle key not provided - trying to get one");
+        credentials.pickleKey =
+            (await PlatformPeg.get()?.getPickleKey(credentials.userId, credentials.deviceId)) ?? undefined;
+    }
+
+    return doSetLoggedIn(credentials, overwrite, false);
+}
+
 /**
  * When we have a authenticated via OIDC-native flow and have a refresh token
  * try to create a token refresher.

src/components/structures/auth/SoftLogout.tsx

@@ -168,7 +168,7 @@ export default class SoftLogout extends React.Component<IProps, IState> {
             return;
         }
 
-        Lifecycle.setLoggedIn(credentials).catch((e) => {
+        Lifecycle.hydrateSession(credentials).catch((e) => {
             logger.error(e);
             this.setState({ busy: false, errorText: _t("auth|failed_soft_logout_auth") });
         });
@@ -204,7 +204,7 @@ export default class SoftLogout extends React.Component<IProps, IState> {
             return false;
         }
 
-        return Lifecycle.setLoggedIn(credentials)
+        return Lifecycle.hydrateSession(credentials)
             .then(() => {
                 if (this.props.onTokenLoginCompleted) {
                     this.props.onTokenLoginCompleted();