setting mountpoint mounts all snapshots

[JMoVS]

When setting a mountpoint, ZFS mounts all datasets even when the snapdir setting is set to hidden.

Reproduce:

1. Create dataset
2. Set snapdir to hidden
3. make some snapshots
4. set mountpoint

results in all snapshots available getting mounted (can be a looooot)

[JMoVS]

@lundman Was that recently fixed in one of the commits?

[will-riley]

Did you get past this? Same problem here, v1.9.4 on Mojave

[JMoVS]

it's still happening but you can cancel that process with ctr-c while it's mounting

[lundman]

I believe it doesn't happen on the new port, as that is handled differently... maybe