Make Save button respond properly on changes in NTP Servers section

Fixes https://bugzilla.redhat.com/show_bug.cgi?id=1749841

Make the button respond properly while editing an existing Zone.

app/controllers/ops_controller/settings/common.rb

@@ -806,6 +806,8 @@ def settings_get_form_vars
       field = "ntp_server_#{field_num}"
       next unless params.key?(field)
       @edit[:new][:ntp][field] = params[field]
+      # remove unnecessary key from @edit[:new][:ntp] if there is no change
+      @edit[:new][:ntp].except!(field) if params[field] == @edit[:new][:ntp][:server][field_num - 1]
     end
   end
 

spec/controllers/ops_controller/settings/common_spec.rb

@@ -47,10 +47,8 @@
         @edit = session[:edit]
       end
 
-      context "#smartproxy_affinity_field_changed" do
-        before do
-          expect(controller).to receive(:render)
-        end
+      describe "#smartproxy_affinity_field_changed" do
+        before { expect(controller).to receive(:render) }
 
         it "should select a host when checked" do
           controller.params = {:id => "xx-#{@svr1.id}__host_#{@host2.id}", :check => '1'}
@@ -115,7 +113,7 @@
         end
       end
 
-      context "#smartproxy_affinity_update" do
+      describe "#smartproxy_affinity_update" do
         it "updates the SmartProxy host affinities" do
           @svr1.vm_scan_host_affinity = []
           @svr2.vm_scan_host_affinity = []
@@ -138,8 +136,9 @@
       end
     end
 
-    context "#settings_update" do
+    describe "#settings_update" do
       let(:orgs) { [1] }
+
       before do
         session[:edit] = {
           :key           => "settings_rhn_edit__rhn_edit",
@@ -178,7 +177,7 @@
       end
     end
 
-    context "#settings_get_form_vars" do
+    describe "#settings_get_form_vars" do
       before do
         miq_server = FactoryBot.create(:miq_server)
         current = ::Settings.to_hash
@@ -210,6 +209,21 @@
       end
     end
 
+    describe '#settings_get_form_vars_sync_ntp' do
+      before do
+        controller.params = {'ntp_server_2' => '1'}
+        controller.instance_variable_set(:@edit, :current => {:ntp => {:server => ['0', '1', '2']}},
+                                                 :new     => {:ntp => {:server => ['0', '1', '2'], 'ntp_server_2' => ''}})
+      end
+
+      subject { controller.instance_variable_get(:@edit) }
+
+      it 'removes unnecessary key from @edit[:new][:ntp]' do
+        controller.send(:settings_get_form_vars_sync_ntp)
+        expect(subject[:new]).to eq(subject[:current])
+      end
+    end
+
     describe "#pglogical_save_subscriptions" do
       before { allow(controller).to receive(:javascript_flash) }