fix(crypto): Automatically track your own user if the caller doesn't do so

Users of the crypto crate should mark all members that are part of an
E2EE room for tracking, this will of course mark your own user for
tracking.

If the crypto crate user doesn't have any E2EE rooms he may not add any
members to be tracked. The user might still want to inspect their own
E2EE devices and identities. This patch makes sure that our member is
tracked.

Author: poljar

crates/matrix-sdk-crypto/src/identities/manager.rs

@@ -404,6 +404,18 @@ impl IdentityManager {
     pub async fn users_for_key_query(&self) -> Vec<KeysQueryRequest> {
         let users = self.store.users_for_key_query();
 
+        // We always want to track our own user, but in case we aren't in an encrypted
+        // room yet, we won't be tracking ourselves yet. This ensures we are always
+        // tracking ourselves.
+        //
+        // The check for emptiness is done first for performance.
+        let users = if users.is_empty() && !self.store.tracked_users().contains(self.user_id()) {
+            self.update_tracked_users([self.user_id()]).await;
+            self.store.users_for_key_query()
+        } else {
+            users
+        };
+
         if users.is_empty() {
             Vec::new()
         } else {
@@ -665,7 +677,7 @@ pub(crate) mod test {
     #[async_test]
     async fn test_manager_creation() {
         let manager = manager();
-        assert!(manager.users_for_key_query().await.is_empty())
+        assert!(manager.store.tracked_users().is_empty())
     }
 
     #[async_test]
@@ -715,4 +727,19 @@ pub(crate) mod test {
 
         assert!(identity.is_device_signed(&device).is_ok())
     }
+
+    #[async_test]
+    async fn no_tracked_users_key_query_request() {
+        let manager = manager();
+
+        assert!(manager.store.tracked_users().is_empty(), "No users are initially tracked");
+
+        let requests = manager.users_for_key_query().await;
+
+        assert!(!requests.is_empty(), "We query the keys for our own user");
+        assert!(
+            manager.store.tracked_users().contains(manager.user_id()),
+            "Our own user is now tracked"
+        );
+    }
 }