scheduled_messages: Handle scheduled messages to inaccessible users.

Inaccessible users are shown as "Unknown user" in the scheduled
messages list.

web/src/people.ts

@@ -421,11 +421,7 @@ export function get_full_names_for_poll_option(user_ids: number[]): string {
 }
 
 export function get_display_full_name(user_id: number): string {
-    const person = maybe_get_user_by_id(user_id);
-    if (!person) {
-        blueslip.error("Unknown user id", {user_id});
-        return "?";
-    }
+    const person = get_user_by_id_assert_valid(user_id);
 
     if (muted_users.is_user_muted(user_id)) {
         if (should_add_guest_user_indicator(user_id)) {

web/src/scheduled_messages_ui.js

@@ -47,7 +47,10 @@ export function open_scheduled_message_in_compose(scheduled_msg, should_narrow_t
         const recipient_emails = [];
         if (scheduled_msg.to) {
             for (const recipient_id of scheduled_msg.to) {
-                recipient_emails.push(people.get_by_user_id(recipient_id).email);
+                const recipient_user = people.get_by_user_id(recipient_id);
+                if (!recipient_user.is_inaccessible_user) {
+                    recipient_emails.push(recipient_user.email);
+                }
             }
         }
         compose_args = {

web/tests/message_store.test.js

@@ -222,16 +222,23 @@ test("errors", ({disallow_rewire}) => {
         display_recipient: [{id: 92714}],
     };
 
-    blueslip.expect("error", "Unknown user_id in maybe_get_user_by_id", 2);
-    blueslip.expect("error", "Unknown user id", 2); // From person.js
+    blueslip.expect("error", "Unknown user_id in maybe_get_user_by_id", 1);
+    blueslip.expect("error", "Unknown user id", 1); // From person.js
 
     // Expect each to throw two blueslip errors
     // One from message_store.js, one from person.js
     const emails = message_store.get_pm_emails(message);
     assert.equal(emails, "?");
 
-    const names = message_store.get_pm_full_names(message);
-    assert.equal(names, "?");
+    assert.throws(
+        () => {
+            message_store.get_pm_full_names(message);
+        },
+        {
+            name: "Error",
+            message: "Unknown user_id in get_by_user_id: 92714",
+        },
+    );
 
     message = {
         type: "stream",

web/tests/people.test.js

@@ -494,7 +494,7 @@ test_people("get_full_names_for_poll_option", () => {
     assert.equal(names, "Me Myself, Isaac Newton");
 });
 
-test_people("get_display_full_names", () => {
+test_people("get_display_full_names", ({override}) => {
     people.initialize_current_user(me.user_id);
     people.add_active_user(steven);
     people.add_active_user(bob);
@@ -502,7 +502,7 @@ test_people("get_display_full_names", () => {
     people.add_active_user(guest);
     page_params.realm_enable_guest_user_indicator = true;
 
-    const user_ids = [me.user_id, steven.user_id, bob.user_id, charles.user_id, guest.user_id];
+    let user_ids = [me.user_id, steven.user_id, bob.user_id, charles.user_id, guest.user_id];
     let names = people.get_display_full_names(user_ids);
 
     // This doesn't do anything special for the current user. The caller has
@@ -545,6 +545,12 @@ test_people("get_display_full_names", () => {
         "translated: Muted user",
         "translated: Muted user (guest)",
     ]);
+
+    override(settings_data, "user_can_access_all_other_users", () => false);
+    const inaccessible_user_id = 99;
+    user_ids = [me.user_id, steven.user_id, inaccessible_user_id];
+    names = people.get_display_full_names(user_ids, true);
+    assert.deepEqual(names, ["Me Myself", "Steven", "translated: Unknown user"]);
 });
 
 test_people("my_custom_profile_data", () => {

web/tests/reactions.test.js

@@ -40,6 +40,9 @@ const sample_message = {
 
 const channel = mock_esm("../src/channel");
 const message_store = mock_esm("../src/message_store");
+mock_esm("../src/settings_data", {
+    user_can_access_all_other_users: () => true,
+});
 const spectators = mock_esm("../src/spectators", {
     login_to_access() {},
 });