Show red shield for users that become unverified

For any users that we previously verified but that are not unverified, we will
now mark them and rooms they are in with a red shield.

Fixes https://github.com/vector-im/riot-web/issues/12808

src/components/views/right_panel/UserInfo.js

@@ -68,8 +68,10 @@ export const getE2EStatus = (cli, userId, devices) => {
         return hasUnverifiedDevice ? "warning" : "verified";
     }
     const isMe = userId === cli.getUserId();
-    const userVerified = cli.checkUserTrust(userId).isCrossSigningVerified();
-    if (!userVerified) return "normal";
+    const userTrust = cli.checkUserTrust(userId);
+    if (!userTrust.isCrossSigningVerified()) {
+        return userTrust.wasCrossSigningVerified() ? "warning" : "normal";
+    }
 
     const anyDeviceUnverified = devices.some(device => {
         const { deviceId } = device;

src/components/views/rooms/MemberTile.js

@@ -121,10 +121,10 @@ export default createReactClass({
         const cli = MatrixClientPeg.get();
         const { userId } = this.props.member;
         const isMe = userId === cli.getUserId();
-        const userVerified = cli.checkUserTrust(userId).isCrossSigningVerified();
-        if (!userVerified) {
+        const userTrust = cli.checkUserTrust(userId);
+        if (!userTrust.isCrossSigningVerified()) {
             this.setState({
-                e2eStatus: "normal",
+                e2eStatus: userTrust.wasCrossSigningVerified() ? "warning" : "normal",
             });
             return;
         }

src/utils/ShieldUtils.ts

@@ -5,6 +5,7 @@ interface Client {
     getUserId: () => string;
     checkUserTrust: (userId: string) => {
         isCrossSigningVerified: () => boolean
+        wasCrossSigningVerified: () => boolean
     };
     getStoredDevicesForUser: (userId: string) => Promise<[{ deviceId: string }]>;
     checkDeviceTrust: (userId: string, deviceId: string) => {
@@ -29,6 +30,13 @@ export async function shieldStatusForMembership(client: Client, room: Room): Pro
             verified : unverified).push(userId);
         });
 
+    /* Alarm if any unverified users were verified before. */
+    for (const userId of unverified) {
+        if (client.checkUserTrust(userId).wasCrossSigningVerified()) {
+            return "warning";
+        }
+    }
+
     /* Check all verified user devices. */
     /* Don't alarm if no other users are verified  */
     const includeUser = (verified.length > 0) &&    // Don't alarm for self in rooms where nobody else is verified