Special handling of empty or nil BOOTPROTO (see wicked docu).bnc#1175206

src/lib/y2network/autoinst_profile/interface_section.rb

@@ -283,7 +283,8 @@ def init_from_hashes(hash)
       # @param config [Y2Network::ConnectionConfig]
       # @return [Boolean]
       def init_from_config(config)
-        @bootproto = config.bootproto.name
+        # nil bootproto is valid use case (missing explicit setup) - wicked defaults to static then
+        @bootproto = config.bootproto&.name
         @name = config.name
         if config.bootproto == BootProtocol::STATIC && config.ip
           # missing ip is valid scenario for wicked - so use empty string here

src/lib/y2network/boot_protocol.rb

@@ -35,7 +35,7 @@ def all
       # Returns the boot protocol with a given name
       #
       # @param name [String]
-      # @return [BootProtocol,nil] Boot protocol or nil is not found
+      # @return [BootProtocol,nil] Boot protocol or nil if not found
       def from_name(name)
         all.find { |t| t.name == name }
       end

src/lib/y2network/sysconfig/connection_config_writers/base.rb

@@ -40,7 +40,7 @@ def initialize(file)
         #
         # @param conn [Y2Network::ConnectionConfig::Base] Connection to take settings from
         def write(conn)
-          file.bootproto = conn.bootproto.name
+          file.bootproto = conn.bootproto&.name
           file.name = conn.description
           file.lladdr = conn.lladdress
           file.startmode = conn.startmode.to_s