FIX: TL0 users' messages to moderators were not being posted when flagging private messages

lib/guardian.rb

@@ -289,8 +289,10 @@ class Guardian
     (target.is_a?(Group) || target.is_a?(User)) &&
     # User is authenticated
     authenticated? &&
-    # Have to be a basic level at least
+    # Have to be a basic level at least, or are contacting moderators
-    @user.has_trust_level?(SiteSetting.min_trust_to_send_messages) &&
+    (@user.has_trust_level?(SiteSetting.min_trust_to_send_messages) ||
+      (target.is_a?(User) && target.moderator?) ||
+      (target.name == Group[:moderators].name)) &&
     # PMs are enabled
     (is_staff? || SiteSetting.enable_private_messages) &&
     # Can't send PMs to suspended users

spec/components/guardian_spec.rb

@@ -154,11 +154,24 @@ describe Guardian do
       expect(Guardian.new(user).can_send_private_message?(user)).to be_truthy
     end
 
-    it "returns false when you are untrusted" do
+    context "when user is untrusted " do
+      before do
         user.trust_level = TrustLevel[0]
+      end
+
+      it "returns false to another user" do
         expect(Guardian.new(user).can_send_private_message?(another_user)).to be_falsey
       end
 
+      it "returns true to moderator user" do
+        expect(Guardian.new(user).can_send_private_message?(moderator)).to be_truthy
+      end
+
+      it "returns true to moderator group" do
+        expect(Guardian.new(user).can_send_private_message?(Group[:moderators])).to be_truthy
+      end
+    end
+
     it "returns true to another user" do
       expect(Guardian.new(user).can_send_private_message?(another_user)).to be_truthy
     end
@@ -180,6 +193,10 @@ describe Guardian do
         expect(Guardian.new(moderator).can_send_private_message?(another_user)).to be_truthy
         expect(Guardian.new(admin).can_send_private_message?(another_user)).to be_truthy
       end
+
+      it "returns false even to a moderator" do
+        expect(Guardian.new(trust_level_4).can_send_private_message?(moderator)).to be_falsey
+      end
     end
 
     context "target user is suspended" do

spec/components/topic_creator_spec.rb

@@ -3,11 +3,12 @@ require 'rails_helper'
 describe TopicCreator do
 
   let(:user)      { Fabricate(:user, trust_level: TrustLevel[2]) }
+  let(:user2)      { Fabricate(:user, trust_level: TrustLevel[2]) }
   let(:moderator) { Fabricate(:moderator) }
   let(:admin)     { Fabricate(:admin) }
 
   let(:valid_attrs) { Fabricate.attributes_for(:topic) }
-  let(:pm_valid_attrs)  { { raw: 'this is a new post', title: 'this is a new title', archetype: Archetype.private_message, target_usernames: moderator.username } }
+  let(:pm_valid_attrs)  { { raw: 'this is a new post', title: 'this is a new title', archetype: Archetype.private_message, target_usernames: user2.username } }
 
   let(:pm_to_email_valid_attrs) do
     {

spec/models/post_action_spec.rb

@@ -42,10 +42,13 @@ describe PostAction do
       expect { PostAction.act(admin, post, PostActionType.types[:notify_user], message: "WAT") }.not_to raise_error
     end
 
-    it "notify moderators integration test" do
+    context "notify moderators integration test" do
+      let!(:mod)  { moderator }
+
+      before { Group.refresh_automatic_groups! }
+
+      it "flag from TL1 user" do
         post = create_post
-      mod = moderator
-      Group.refresh_automatic_groups!
 
         action = PostAction.act(codinghorror, post, PostActionType.types[:notify_moderators], message: "this is my special long message")
 
@@ -100,6 +103,29 @@ describe PostAction do
         expect(topic.posts.last.post_type).to eq(Post.types[:moderator_action])
       end
 
+      it "flag from TL0 user" do
+        tl0_user = Fabricate(:user, trust_level: 0)
+        first_post = Fabricate(:post, user: Fabricate(:user, trust_level: 1))
+
+        pm_topic = Fabricate(:private_message_topic,
+          first_post: first_post,
+          topic_allowed_users: [
+            Fabricate.build(:topic_allowed_user, user: first_post.user),
+            Fabricate.build(:topic_allowed_user, user: tl0_user),
+          ]
+        )
+
+        action = PostAction.act(tl0_user, first_post, PostActionType.types[:notify_moderators], message: 'my special message')
+
+        expect(action.related_post_id).to be_present
+
+        notify_moderators_post = action.related_post
+
+        expect(notify_moderators_post.topic&.subtype).to eq(TopicSubtype.notify_moderators)
+        expect(notify_moderators_post.raw).to include('my special message')
+      end
+    end
+
     describe 'notify_moderators' do
       before do
         PostAction.stubs(:create)