Do not route to managing org if it can be inferred

app/models/form/lettings/pages/managing_organisation.rb

@@ -20,6 +20,7 @@ class Form::Lettings::Pages::ManagingOrganisation < ::Form::Page
                    end
 
     return false unless organisation
+    return false if log.owning_organisation != organisation && !organisation.holds_own_stock?
     return true unless organisation.holds_own_stock?
 
     organisation.managing_agents.count >= 1

spec/models/form/lettings/pages/managing_organisation_spec.rb

@@ -105,15 +105,30 @@ RSpec.describe Form::Lettings::Pages::ManagingOrganisation, type: :model do
 
     context "when not support" do
       context "when does not hold own stock" do
-        let(:user) do
-          create(:user, :data_coordinator, organisation: create(:organisation, holds_own_stock: false))
-        end
+        let(:user) { create(:user, :data_coordinator, organisation: create(:organisation, holds_own_stock: false)) }
+
+        context "and the user's organisation is selected as owning organisation" do
+          let(:log) { create(:lettings_log, owning_organisation: user.organisation) }
 
           it "is shown" do
             expect(page.routed_to?(log, user)).to eq(true)
           end
         end
 
+        context "and a different than the user's organisation is selected as owning organisation" do
+          let(:stock_owner) { create(:organisation, holds_own_stock: true) }
+          let(:log) { create(:lettings_log, owning_organisation: stock_owner) }
+
+          before do
+            create(:organisation_relationship, parent_organisation: stock_owner, child_organisation: user.organisation)
+          end
+
+          it "is not shown" do
+            expect(page.routed_to?(log, user)).to eq(false)
+          end
+        end
+      end
+
       context "when holds own stock" do
         let(:user) do
           create(:user, :data_coordinator, organisation: create(:organisation, holds_own_stock: true))