build/meson: allow configuring default for main.auth-polkit setting

We always build PolicyKit support, because it merely depends on some
D-Bus calls. However, there are two things to configure:

 - the default value for main.auth-polkit in NetworkManager.conf. This
   is now called "-Dconfig_auth_polkit_default=$VAL".

 - whether to install the policy file. This is called "-Dpolkit=$VAL".

These settings are mostly independent, so add "config_auth_polkit_default" to
make the default explicitly configurable.

contrib/fedora/rpm/NetworkManager.spec

@@ -585,6 +585,7 @@ This tool is still experimental.
 %endif
 	-Dselinux=true \
 	-Dpolkit=true  \
+	-Dconfig_auth_polkit_default=true \
 	-Dpolkit_agent=true \
 	-Dmodify_system=true \
 	-Dconcheck=true \

meson.build

@@ -464,8 +464,11 @@ if enable_polkit
   polkit_gobject_policydir = dependency('polkit-gobject-1').get_pkgconfig_variable('policydir', define_variable: ['prefix', nm_prefix])
 endif
 
-config_default_main_auth_polkit = enable_polkit.to_string()
+config_auth_polkit_default = get_option('config_auth_polkit_default')
-config_h.set_quoted('NM_CONFIG_DEFAULT_MAIN_AUTH_POLKIT', config_default_main_auth_polkit)
+if config_auth_polkit_default == 'default'
+  config_auth_polkit_default = (enable_polkit ? 'true' : 'false')
+endif
+config_h.set_quoted('NM_CONFIG_DEFAULT_MAIN_AUTH_POLKIT', config_auth_polkit_default)
 
 enable_modify_system = get_option('modify_system')
 
@@ -784,7 +787,7 @@ data_conf = configuration_data()
 data_conf.set('DISTRO_NETWORK_SERVICE',                  (enable_ifcfg_rh ? 'network.service' : ''))
 data_conf.set('NM_CONFIG_DEFAULT_LOGGING_AUDIT_TEXT',    config_default_logging_audit)
 data_conf.set('NM_CONFIG_DEFAULT_LOGGING_BACKEND_TEXT',  config_logging_backend_default)
-data_conf.set('NM_CONFIG_DEFAULT_MAIN_AUTH_POLKIT_TEXT', config_default_main_auth_polkit)
+data_conf.set('NM_CONFIG_DEFAULT_MAIN_AUTH_POLKIT_TEXT', config_auth_polkit_default)
 data_conf.set('NM_CONFIG_DEFAULT_MAIN_DHCP',             config_dhcp_default)
 data_conf.set('NM_CONFIG_DEFAULT_MAIN_RC_MANAGER',       config_dns_rc_manager_default)
 data_conf.set('NM_MAJOR_VERSION',                        nm_major_version)
@@ -935,10 +938,9 @@ output += '  nmplugindir: ' + nm_plugindir + '\n'
 output += '\nPlatform:\n'
 output += '  session tracking: ' + ','.join(session_trackers) + '\n'
 output += '  suspend/resume: ' + suspend_resume + '\n'
-output += '  policykit: ' + enable_polkit.to_string()
+output += '  policykit: ' + enable_polkit.to_string() + ' (default: ' + config_auth_polkit_default + ')'
 if enable_polkit
-  modify = (enable_modify_system ? 'permissive' : 'restrictive')
+  output += ' (' + (enable_modify_system ? 'permissive' : 'restrictive') + ' modify.system)'
-  output += ' (' + modify + ' modify.system) (default: main.auth-polkit=true)'
 endif
 output += '\n'
 output += '  polkit agent: ' + enable_polkit_agent.to_string() + '\n'

meson_options.txt

@@ -14,6 +14,7 @@ option('session_tracking_consolekit', type: 'boolean', value: true, description:
 option('session_tracking', type: 'combo', choices: ['systemd', 'elogind', 'no'], value: 'systemd', description: 'Compatibility option to choose one session tracking module')
 option('suspend_resume', type: 'combo', choices: ['upower', 'systemd', 'elogind', 'consolekit', 'auto'], value: 'auto', description: 'Build NetworkManager with specific suspend/resume support')
 option('polkit', type: 'boolean', value: true, description: 'User auth-polkit configuration option.')
+option('config_auth_polkit_default', type: 'combo', choices: ['default', 'true', 'false'], value: 'default', description: 'Default value for configuration main.auth-polkit.')
 option('modify_system', type: 'boolean', value: false, description: 'Allow users to modify system connections')
 option('polkit_agent', type: 'boolean', value: false, description: 'enable polkit agent for clients')
 option('selinux', type: 'boolean', value: true, description: 'Build with SELinux')