Description of problem:
When changing an 802-3-ethernet connection's master from bridge to a bond it is not reconnected unless reactivated explicitly (although 802-3-ethernet connection has autoconnect set to true and bond connection has autoconnect-slaves set to 1). Not sure if it is a bug, mistake in config or a missing feature.


Version-Release number of selected component (if applicable):
CentOS Linux release 7.3.1611 (Core)
NetworkManager 1.4.0

How reproducible:
Always

Steps to Reproduce:
1. Create an 802-3-ethernet and bridge connections, 802-3-ethernet connection master is set to the bridge.
2. Interfaces are now autoconnected eth0-br1
3. Create a new connection for bond and change 802-3-ethernet connection master to this new bond.

Actual results:
802-3-ethernet master is still set to bridge.

Expected results:
802-3-ethernet master is set to bond1.

Reproducer script:
import uuid
import dbus

bus = dbus.SystemBus()
proxy = bus.get_object('org.freedesktop.NetworkManager', '/org/freedesktop/NetworkManager/Settings')
settings = dbus.Interface(proxy, 'org.freedesktop.NetworkManager.Settings')

ethernet_conn_settings = dbus.Dictionary({
    'connection': dbus.Dictionary({
        'id': 'test-eth0',
        'interface-name': 'eth0',
        'uuid': str(uuid.uuid4()),
        'type': '802-3-ethernet',
        'autoconnect': True,
        'autoconnect-priority': 100,
        'master': 'br0',
        'slave-type': 'bridge'
    })
})
bridge_conn_settings = dbus.Dictionary({
    'connection': dbus.Dictionary({
        'id': 'test-br0',
        'interface-name': 'br0',
        'uuid': str(uuid.uuid4()),
        'type': 'bridge',
        'autoconnect': True,
        'autoconnect-priority': 100,
        'autoconnect-slaves': True
    })
})
settings.AddConnection(ethernet_conn_settings)
settings.AddConnection(bridge_conn_settings)

import time
time.sleep(10)

bond_conn_settings = dbus.Dictionary({
    'connection': dbus.Dictionary({
        'id': 'test-bond1',
        'interface-name': 'bond1',
        'uuid': str(uuid.uuid4()),
        'type': 'bond',
        'autoconnect': True,
        'autoconnect-priority': 100,
        'master': 'br0',
        'slave-type': 'bridge',
        'autoconnect-slaves': True
    })
})
ethernet_conn = None
ethernet_conn_uuid = None
for conn in settings.ListConnections():
    con_proxy = bus.get_object('org.freedesktop.NetworkManager', conn)
    settings_connection = dbus.Interface(con_proxy, 'org.freedesktop.NetworkManager.Settings.Connection')
    config = settings_connection.GetSettings()
    if str(config['connection']['id']) == 'test-eth0':
        ethernet_conn = settings_connection
        ethernet_conn_uuid = str(config['connection']['uuid'])
ethernet_conn_settings['connection'].update({
    'slave-type': 'bond',
    'master': 'bond1',
    'uuid': ethernet_conn_uuid
})
ethernet_conn.Update(ethernet_conn_settings)
settings.AddConnection(bond_conn_settings)

After running this `ip link` returns:
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN mode DEFAULT qlen 1
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast master br0 state UP mode DEFAULT qlen 1000
    link/ether 52:54:00:e6:eb:82 brd ff:ff:ff:ff:ff:ff
3: br0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP mode DEFAULT qlen 1000
    link/ether 52:54:00:e6:eb:82 brd ff:ff:ff:ff:ff:ff
4: bond1: <NO-CARRIER,BROADCAST,MULTICAST,MASTER,UP> mtu 1500 qdisc noqueue master br0 state DOWN mode DEFAULT qlen 1000
    link/ether 8e:9c:29:a5:54:4d brd ff:ff:ff:ff:ff:ff

ethernet connection:
[root@localhost tmp]# nmcli con show test-eth0 
...
connection.master:                      bond1
connection.slave-type:                  bond
...