checkpoint: preserve devices that were removed and readded

With flag DISCONNECT_NEW_DEVICES, on rollback we delete devices that
are present in the system and are not in the checkpoint.

The problem is that we remove the device from
`NMCheckpointPriv->devices` when it is deleted and so we lose the
information that the device was in the checkpoint. We need to also
look in the `removed_devices` list.

Fixes: 0e2f7ac7b5 ('nm-checkpoint: drop reference to NM_DEVICE objects on removal signal')
(cherry picked from commit 0fcfd6e24f)

src/core/nm-checkpoint.c

@@ -458,8 +458,25 @@ next_dev:
         NMDeviceState state;
 
         nm_manager_for_each_device (priv->manager, device, tmp_lst) {
+            gboolean found = FALSE;
+
             if (g_hash_table_contains(priv->devices, device))
                 continue;
+
+            /* Also ignore devices that were in the checkpoint initially and
+             * were moved to 'removed_devices' because they got removed from
+             * the system. */
+            for (i = 0; i < priv->removed_devices->len; i++) {
+                dev_checkpoint = priv->removed_devices->pdata[i];
+                if (dev_checkpoint->dev_type == nm_device_get_device_type(device)
+                    && nm_streq0(dev_checkpoint->original_dev_name, nm_device_get_iface(device))) {
+                    found = TRUE;
+                    break;
+                }
+            }
+            if (found)
+                continue;
+
             state = nm_device_get_state(device);
             if (state > NM_DEVICE_STATE_DISCONNECTED && state < NM_DEVICE_STATE_DEACTIVATING) {
                 _LOGD("rollback: disconnecting new device %s", nm_device_get_iface(device));