FIX: Moderators shouldn't be able to see secure deleted posts

app/controllers/posts_controller.rb

@@ -335,7 +335,7 @@ class PostsController < ApplicationController
     offset = [params[:offset].to_i, 0].max
     limit = [(params[:limit] || 60).to_i, 100].min
 
-    posts = user_posts(user.id, offset, limit)
+    posts = user_posts(guardian, user.id, offset: offset, limit: limit)
               .where(id: PostAction.where(post_action_type_id: PostActionType.notify_flag_type_ids)
                                    .where(disagreed_at: nil)
                                    .select(:post_id))
@@ -351,7 +351,7 @@ class PostsController < ApplicationController
     offset = [params[:offset].to_i, 0].max
     limit = [(params[:limit] || 60).to_i, 100].min
 
-    posts = user_posts(user.id, offset, limit).where.not(deleted_at: nil)
+    posts = user_posts(guardian, user.id, offset: offset, limit: limit).where.not(deleted_at: nil)
 
     render_serialized(posts, AdminPostSerializer)
   end
@@ -389,13 +389,26 @@ class PostsController < ApplicationController
 
   private
 
-  def user_posts(user_id, offset=0, limit=60)
-    Post.includes(:user, :topic, :deleted_by, :user_actions)
-        .with_deleted
-        .where(user_id: user_id)
-        .order(created_at: :desc)
-        .offset(offset)
-        .limit(limit)
+  def user_posts(guardian, user_id, opts)
+    posts = Post.includes(:user, :topic, :deleted_by, :user_actions)
+                .where(user_id: user_id)
+                .with_deleted
+                .order(created_at: :desc)
+
+    if guardian.user.moderator?
+
+      # Awful hack, but you can't seem to remove the `default_scope` when joining
+      # So instead I grab the topics separately
+      topic_ids = posts.dup.pluck(:topic_id)
+      secured_category_ids = guardian.secure_category_ids
+      topics = Topic.where(id: topic_ids).with_deleted.where.not(archetype: 'private_message')
+      topics = topics.secured(guardian)
+
+      posts = posts.where(topic_id: topics.pluck(:id))
+    end
+
+    posts.offset(opts[:offset])
+         .limit(opts[:limit])
   end
 
   def params_key(params)

spec/controllers/posts_controller_spec.rb

@@ -774,6 +774,43 @@ describe PostsController do
         expect(response).to be_success
       end
 
+      it "doesn't return secured categories for moderators if they don't have access" do
+        user = Fabricate(:user)
+        admin = Fabricate(:admin)
+        moderator = Fabricate(:moderator)
+
+        group = Fabricate(:group)
+        group.add(user)
+        group.appoint_manager(user)
+
+        secured_category = Fabricate(:private_category, group: group)
+        secured_post = create_post(user: user, category: secured_category)
+        PostDestroyer.new(admin, secured_post).destroy
+
+        log_in(:moderator)
+        xhr :get, :deleted_posts, username: user.username
+        expect(response).to be_success
+
+        data = JSON.parse(response.body)
+        expect(data.length).to eq(0)
+      end
+
+      it "doesn't return PMs for moderators" do
+        user = Fabricate(:user)
+        admin = Fabricate(:admin)
+        moderator = Fabricate(:moderator)
+
+        pm_post = create_post(user: user, archetype: 'private_message', target_usernames: [admin.username])
+        PostDestroyer.new(admin, pm_post).destroy
+
+        log_in(:moderator)
+        xhr :get, :deleted_posts, username: user.username
+        expect(response).to be_success
+
+        data = JSON.parse(response.body)
+        expect(data.length).to eq(0)
+      end
+
       it "only shows posts deleted by other users" do
         user = Fabricate(:user)
         admin = Fabricate(:admin)

spec/fabricators/category_fabricator.rb

@@ -22,6 +22,6 @@ Fabricator(:private_category, from: :category) do
   user
   after_build do |cat, transients|
     cat.update!(read_restricted: true)
-    cat.category_groups.build(group_id: transients[:group].id, permission_type: :full)
+    cat.category_groups.build(group_id: transients[:group].id, permission_type: CategoryGroup.permission_types[:full])
   end
 end