libnm: move backported symbols from libnm-core to libnm

Backported symbols only make sense for libnm itself, not for
libnm-core which is statically linked with NetworkManager and
nm-ifcace-helper. Declaring the symbols in libnm-core, means
that NetworkManager binary also contains them, although there
are not used.

Move them to libnm.

libnm-core/nm-setting-connection.c

@@ -647,9 +647,6 @@ nm_setting_connection_get_autoconnect_slaves (NMSettingConnection *setting)
 
 	return NM_SETTING_CONNECTION_GET_PRIVATE (setting)->autoconnect_slaves;
 }
-NM_BACKPORT_SYMBOL (libnm_1_0_4, NMSettingConnectionAutoconnectSlaves, nm_setting_connection_get_autoconnect_slaves, (NMSettingConnection *setting), (setting));
-
-NM_BACKPORT_SYMBOL (libnm_1_0_4, GType, nm_setting_connection_autoconnect_slaves_get_type, (void), ());
 
 /**
  * nm_setting_connection_get_num_secondaries:
@@ -804,10 +801,6 @@ nm_setting_connection_get_metered (NMSettingConnection *setting)
 	return NM_SETTING_CONNECTION_GET_PRIVATE (setting)->metered;
 }
 
-NM_BACKPORT_SYMBOL (libnm_1_0_6, NMMetered, nm_setting_connection_get_metered, (NMSettingConnection *setting), (setting));
-
-NM_BACKPORT_SYMBOL (libnm_1_0_6, GType, nm_metered_get_type, (void), ());
-
 /**
  * nm_setting_connection_get_lldp:
  * @setting: the #NMSettingConnection

libnm-core/nm-setting-ip-config.c

@@ -1773,7 +1773,6 @@ nm_setting_ip_config_get_dns_priority (NMSettingIPConfig *setting)
 
 	return NM_SETTING_IP_CONFIG_GET_PRIVATE (setting)->dns_priority;
 }
-NM_BACKPORT_SYMBOL (libnm_1_2_4, gint, nm_setting_ip_config_get_dns_priority, (NMSettingIPConfig *setting), (setting));
 
 /**
  * nm_setting_ip_config_get_num_addresses:

libnm-core/nm-setting-wired.c

@@ -594,8 +594,6 @@ nm_setting_wired_get_wake_on_lan (NMSettingWired *setting)
 
 	return NM_SETTING_WIRED_GET_PRIVATE (setting)->wol;
 }
-NM_BACKPORT_SYMBOL (libnm_1_0_6, NMSettingWiredWakeOnLan, nm_setting_wired_get_wake_on_lan,
-                    (NMSettingWired *setting), (setting));
 
 /**
  * nm_setting_wired_get_wake_on_lan_password:
@@ -615,10 +613,6 @@ nm_setting_wired_get_wake_on_lan_password (NMSettingWired *setting)
 
 	return NM_SETTING_WIRED_GET_PRIVATE (setting)->wol_password;
 }
-NM_BACKPORT_SYMBOL (libnm_1_0_6, const char *, nm_setting_wired_get_wake_on_lan_password,
-                    (NMSettingWired *setting), (setting));
-
-NM_BACKPORT_SYMBOL (libnm_1_0_6, GType, nm_setting_wired_wake_on_lan_get_type, (void), ());
 
 static gboolean
 verify (NMSetting *setting, NMConnection *connection, GError **error)

libnm-core/nm-utils.c

@@ -2904,7 +2904,6 @@ nm_utils_wifi_2ghz_freqs (void)
 {
 	return _wifi_freqs (TRUE);
 }
-NM_BACKPORT_SYMBOL (libnm_1_0_6, const guint *, nm_utils_wifi_2ghz_freqs, (void), ());
 
 /**
  * nm_utils_wifi_5ghz_freqs:
@@ -2920,7 +2919,6 @@ nm_utils_wifi_5ghz_freqs (void)
 {
 	return _wifi_freqs (FALSE);
 }
-NM_BACKPORT_SYMBOL (libnm_1_0_6, const guint *, nm_utils_wifi_5ghz_freqs, (void), ());
 
 /**
  * nm_utils_wifi_strength_bars:
@@ -4277,8 +4275,6 @@ char *nm_utils_enum_to_str (GType type, int value)
 	g_type_class_unref (class);
 	return ret;
 }
-NM_BACKPORT_SYMBOL (libnm_1_0_6, char *, nm_utils_enum_to_str,
-                    (GType type, int value), (type, value));
 
 /**
  * nm_utils_enum_from_str:
@@ -4350,9 +4346,6 @@ gboolean nm_utils_enum_from_str (GType type, const char *str,
 	g_type_class_unref (class);
 	return ret;
 }
-NM_BACKPORT_SYMBOL (libnm_1_0_6, gboolean, nm_utils_enum_from_str,
-                    (GType type, const char *str, int *out_value, char **err_token),
-                    (type, str, out_value, err_token));
 
 /**
  * nm_utils_enum_get_values:

libnm/nm-client.c

@@ -2419,3 +2419,50 @@ nm_client_async_initable_iface_init (GAsyncInitableIface *iface)
 	iface->init_async = init_async;
 	iface->init_finish = init_finish;
 }
+
+/*****************************************************************************
+ * Backported symbols. Usually, new API is only added in new major versions
+ * of NetworkManager (that is, on "master" branch). Sometimes however, we might
+ * have to backport some API to an older stable branch. In that case, we backport
+ * the symbols with a different version corresponding to the minor API.
+ *
+ * To allow upgrading from such a extended minor-release, "master" contains these
+ * backported symbols too.
+ *
+ * For example, 1.2.0 added nm_setting_connection_autoconnect_slaves_get_type.
+ * This was backported for 1.0.4 as nm_setting_connection_autoconnect_slaves_get_type@libnm_1_0_4
+ * To allow an application that was linked against 1.0.4 to seamlessly upgrade to
+ * a newer major version, the same symbols is also exposed on "master". Note, that
+ * a user can only seamlessly upgrade to a newer major version, that is released
+ * *after* 1.0.4 is out. In this example, 1.2.0 was released after 1.4.0, and thus
+ * a 1.0.4 user can upgrade to 1.2.0 ABI.
+ *****************************************************************************/
+
+NM_BACKPORT_SYMBOL (libnm_1_0_4, NMSettingConnectionAutoconnectSlaves, nm_setting_connection_get_autoconnect_slaves, (NMSettingConnection *setting), (setting));
+
+NM_BACKPORT_SYMBOL (libnm_1_0_4, GType, nm_setting_connection_autoconnect_slaves_get_type, (void), ());
+
+NM_BACKPORT_SYMBOL (libnm_1_0_6, NMMetered, nm_setting_connection_get_metered, (NMSettingConnection *setting), (setting));
+
+NM_BACKPORT_SYMBOL (libnm_1_0_6, GType, nm_metered_get_type, (void), ());
+
+NM_BACKPORT_SYMBOL (libnm_1_0_6, NMSettingWiredWakeOnLan, nm_setting_wired_get_wake_on_lan,
+                    (NMSettingWired *setting), (setting));
+
+NM_BACKPORT_SYMBOL (libnm_1_0_6, const char *, nm_setting_wired_get_wake_on_lan_password,
+                    (NMSettingWired *setting), (setting));
+
+NM_BACKPORT_SYMBOL (libnm_1_0_6, GType, nm_setting_wired_wake_on_lan_get_type, (void), ());
+
+NM_BACKPORT_SYMBOL (libnm_1_0_6, const guint *, nm_utils_wifi_2ghz_freqs, (void), ());
+
+NM_BACKPORT_SYMBOL (libnm_1_0_6, const guint *, nm_utils_wifi_5ghz_freqs, (void), ());
+
+NM_BACKPORT_SYMBOL (libnm_1_0_6, char *, nm_utils_enum_to_str,
+                    (GType type, int value), (type, value));
+
+NM_BACKPORT_SYMBOL (libnm_1_0_6, gboolean, nm_utils_enum_from_str,
+                    (GType type, const char *str, int *out_value, char **err_token),
+                    (type, str, out_value, err_token));
+
+NM_BACKPORT_SYMBOL (libnm_1_2_4, gint, nm_setting_ip_config_get_dns_priority, (NMSettingIPConfig *setting), (setting));