simplify UI preferences change logic

I copied the example of the password field by introducing a setter.
But I forgot: it was only that way because the password field has
the complexity of hashing/salting. For fields where setting is
idempotent, it can be directly exposed.

server/db/auth.rs

@@ -90,7 +90,7 @@ impl User {
             username: self.username.clone(),
             flags: self.flags,
             set_password_hash: None,
-            set_preferences: None,
+            preferences: self.preferences.clone(),
             unix_uid: self.unix_uid,
             permissions: self.permissions.clone(),
         }
@@ -116,7 +116,7 @@ pub struct UserChange {
     pub username: String,
     pub flags: i32,
     set_password_hash: Option<Option<String>>,
-    set_preferences: Option<UserPreferences>,
+    pub preferences: UserPreferences,
     pub unix_uid: Option<i32>,
     pub permissions: Permissions,
 }
@@ -128,7 +128,7 @@ impl UserChange {
             username,
             flags: 0,
             set_password_hash: None,
-            set_preferences: None,
+            preferences: UserPreferences::default(),
             unix_uid: None,
             permissions: Permissions::default(),
         }
@@ -143,10 +143,6 @@ impl UserChange {
         self.set_password_hash = Some(None);
     }
 
-    pub fn set_preferences(&mut self, preferences: UserPreferences) {
-        self.set_preferences = Some(preferences);
-    }
-
     pub fn disable(&mut self) {
         self.flags |= UserFlag::Disabled as i32;
     }
@@ -465,10 +461,6 @@ impl State {
             ::std::collections::btree_map::Entry::Vacant(_) => panic!("missing uid {}!", id),
             ::std::collections::btree_map::Entry::Occupied(e) => e,
         };
-        let preferences = change.set_preferences.unwrap_or_else(|| {
-            let u = e.get();
-            u.preferences.clone()
-        });
         {
             let (phash, pid, pcount) = match change.set_password_hash.as_ref() {
                 None => {
@@ -490,7 +482,7 @@ impl State {
                 ":unix_uid": &change.unix_uid,
                 ":id": &id,
                 ":permissions": &permissions,
-                ":preferences": &preferences,
+                ":preferences": &change.preferences,
             })?;
         }
         let u = e.into_mut();
@@ -503,7 +495,7 @@ impl State {
         u.flags = change.flags;
         u.unix_uid = change.unix_uid;
         u.permissions = change.permissions;
-        u.preferences = preferences;
+        u.preferences = change.preferences;
         Ok(u)
     }
 
@@ -521,14 +513,13 @@ impl State {
             .permissions
             .write_to_bytes()
             .expect("proto3->vec is infallible");
-        let preferences = change.set_preferences.unwrap_or_default();
         stmt.execute(named_params! {
             ":username": &change.username[..],
             ":password_hash": &password_hash,
             ":flags": &change.flags,
             ":unix_uid": &change.unix_uid,
             ":permissions": &permissions,
-            ":preferences": &preferences,
+            ":preferences": &change.preferences,
         })?;
         let id = conn.last_insert_rowid() as i32;
         self.users_by_name.insert(change.username.clone(), id);
@@ -547,7 +538,7 @@ impl State {
             unix_uid: change.unix_uid,
             dirty: false,
             permissions: change.permissions,
-            preferences,
+            preferences: change.preferences,
         }))
     }
 
@@ -1340,16 +1331,13 @@ mod tests {
         db::init(&mut conn).unwrap();
         let mut state = State::init(&conn).unwrap();
         let mut change = UserChange::add_user("slamb".to_owned());
-        let mut preferences = UserPreferences::default();
+        change.preferences.0.insert("foo".to_string(), 42.into());
-        preferences.0.insert("foo".to_string(), 42.into());
-        change.set_preferences(preferences.clone());
         let u = state.apply(&conn, change).unwrap();
-        assert_eq!(preferences, u.preferences);
         let mut change = u.change();
-        preferences.0.insert("bar".to_string(), 26.into());
+        change.preferences.0.insert("bar".to_string(), 26.into());
-        change.set_preferences(preferences.clone());
         let u = state.apply(&conn, change).unwrap();
-        assert_eq!(preferences, u.preferences);
+        assert_eq!(u.preferences.0.get("foo"), Some(&42.into()));
+        assert_eq!(u.preferences.0.get("bar"), Some(&26.into()));
         let uid = u.id;
 
         {
@@ -1359,6 +1347,7 @@ mod tests {
         }
         let state = State::init(&conn).unwrap();
         let u = state.users_by_id().get(&uid).unwrap();
-        assert_eq!(preferences, u.preferences);
+        assert_eq!(u.preferences.0.get("foo"), Some(&42.into()));
+        assert_eq!(u.preferences.0.get("bar"), Some(&26.into()));
     }
 }

server/src/web.rs

@@ -1042,7 +1042,7 @@ impl Service {
         if let Some(update) = r.update {
             let mut change = user.change();
             if let Some(preferences) = update.preferences {
-                change.set_preferences(preferences);
+                change.preferences = preferences;
             }
             db.apply_user_change(change).map_err(internal_server_err)?;
         }