StatusView: Handle badly formatted emoji reactions.

lib/pleroma/web/mastodon_api/views/status_view.ex

@@ -297,13 +297,17 @@ def render("show.json", %{activity: %{data: %{"object" => _object}} = activity}
 
     emoji_reactions =
       with %{data: %{"reactions" => emoji_reactions}} <- object do
-        Enum.map(emoji_reactions, fn [emoji, users] ->
-          %{
-            name: emoji,
-            count: length(users),
-            me: !!(opts[:for] && opts[:for].ap_id in users)
-          }
+        Enum.map(emoji_reactions, fn
+          [emoji, users] when is_list(users) ->
+            build_emoji_map(emoji, users, opts[:for])
+
+          {emoji, users} when is_list(users) ->
+            build_emoji_map(emoji, users, opts[:for])
+
+          _ ->
+            nil
         end)
+        |> Enum.reject(&is_nil/1)
       else
         _ -> []
       end
@@ -545,4 +549,12 @@ defp present?(_), do: true
 
   defp pinned?(%Activity{id: id}, %User{pinned_activities: pinned_activities}),
     do: id in pinned_activities
+
+  defp build_emoji_map(emoji, users, current_user) do
+    %{
+      name: emoji,
+      count: length(users),
+      me: !!(current_user && current_user.ap_id in users)
+    }
+  end
 end

test/web/mastodon_api/views/status_view_test.exs

@@ -56,6 +56,23 @@ test "has an emoji reaction list" do
            ]
   end
 
+  test "works correctly with badly formatted emojis" do
+    user = insert(:user)
+    {:ok, activity} = CommonAPI.post(user, %{status: "yo"})
+
+    activity
+    |> Object.normalize(false)
+    |> Object.update_data(%{"reactions" => %{"☕" => [user.ap_id], "x" => 1}})
+
+    activity = Activity.get_by_id(activity.id)
+
+    status = StatusView.render("show.json", activity: activity, for: user)
+
+    assert status[:pleroma][:emoji_reactions] == [
+             %{name: "☕", count: 1, me: true}
+           ]
+  end
+
   test "loads and returns the direct conversation id when given the `with_direct_conversation_id` option" do
     user = insert(:user)