openhab-core: [thing actions] Actions fail to execute after a binding restart

Reference my comment here.

Most (if not all) thing action implementations contain code that looks like this.

    public static void restart(@Nullable ThingActions actions) {
        if (actions instanceof DoorbirdActions) {
            ((DoorbirdActions) actions).restart();
        } else {
            throw new IllegalArgumentException("Instance is not a DoorbirdActionsService class");
        }
    }

Normally, the instanceof test succeeds. However, after installing a new version of the binding, this test fails, which causes the code to throw IllegalArgumentException when invoking the action from a rule. This condition can only be cleared by restarting openHAB. There are several ways to reproduce this, one of which is to drop a new version of a binding into addons that overwrites an older version that’s already there.

After installing the new version of the binding, it appears that the classloader instances are different. I suspect this is what’s causing the instanceof test to fail.

Before installing new binding version:

2019-12-09 09:23:02.018 [INFO ] [ding.doorbird.action.DoorbirdActions] - DoorbirdActions classloader org.eclipse.osgi.internal.loader.EquinoxClassLoader@50578098[org.openhab.binding.doorbird:2.5.0.201912091420(id=245)]
2019-12-09 09:23:02.019 [INFO ] [ding.doorbird.action.DoorbirdActions] - ThingActions actions classloader org.eclipse.osgi.internal.loader.EquinoxClassLoader@50578098[org.openhab.binding.doorbird:2.5.0.201912091420(id=245)]

After installing new binding version:

2019-12-09 09:24:39.813 [INFO ] [ding.doorbird.action.DoorbirdActions] - DoorbirdActions classloader org.eclipse.osgi.internal.loader.EquinoxClassLoader@50578098[org.openhab.binding.doorbird:2.5.0.201912091423(id=245)]
2019-12-09 09:24:39.814 [INFO ] [ding.doorbird.action.DoorbirdActions] - ThingActions actions classloader org.eclipse.osgi.internal.loader.EquinoxClassLoader@1c14e241[org.openhab.binding.doorbird:2.5.0.201912091423(id=245)]