Changes based on CR.

src/include/network/services/dns.rb

@@ -385,8 +385,7 @@ def InitDhcpHostname(_key)
         Item(Id(:any), _("yes: any"), dhcp_hostname == :any)
       ]
 
-      config = Yast::Lan.yast_config
-      iface_names = config.connections.to_a.select { |c| c.bootproto.dhcp? }.map(&:interface)
+      iface_names = config.connections.to_a.select(&:dhcp?).map(&:interface)
       items += iface_names.map do |iface|
         # translators: label is in form yes: <device name>
         Item(Id(iface), format(_("yes: %s"), iface), dhcp_hostname == iface)
@@ -631,13 +630,17 @@ def DNSMainDialog(_standalone)
       ret
     end
 
+    def config
+      Yast::Lan.yast_config
+    end
+
     # Checks if any interface is configured to use DHCP
     #
     # @return [Boolean] true when an interface uses DHCP config
     def dhcp?
-      config = Yast::Lan.yast_config
+      return false unless config&.connections
 
-      !!config&.connections&.any? { |c| c.bootproto&.dhcp? }
+      config.connections.any?(&:dhcp?)
     end
   end
 end

src/lib/y2network/connection_config/base.rb

@@ -189,6 +189,12 @@ def find_master(configs)
         end
       end
 
+      def dhcp?
+        return false unless bootproto
+
+        bootproto.dhcp?
+      end
+
     private
 
       def replace_ifplugd?

src/lib/y2network/presenters/dns_summary.rb

@@ -53,9 +53,10 @@ def text
     private
 
       def dhcp_hostname?
-        return false unless config.connections.any? { |c| c.bootproto&.dhcp? }
+        return false unless hostname.dhcp_hostname
+        return false unless config.connections.any?(&:dhcp?)
 
-        hostname.dhcp_hostname && hostname.dhcp_hostname != :none
+        hostname.dhcp_hostname != :none
       end
 
       def add_hostname(summary)

test/y2network/presenters/dns_summary_test.rb

@@ -31,8 +31,10 @@
   end
 
   let(:config) do
-    Y2Network::Config.new(interfaces: interfaces, connections: connections,
-                          source: :testing, hostname: hostname, dns: dns)
+    Y2Network::Config.new(
+      interfaces: interfaces, connections: connections,
+      source: :testing, hostname: hostname, dns: dns
+    )
   end
 
   let(:eth0) do