Upvoting in example-forum demo broken

[exilef]

Hi,

it seems like the upvoting feature of the example-forum demo is broken. Specifically, two things do not work as expected:

1. A single user can upvote one post several times. How can this be prevented?
2. When clicking the up vote button, the counter first jumps back by one, then increases by one (i.e. from 2 to 1 and then quickly to the correct value 3).

I am using a fresh install of the the latest version eb5f6aada70db7296a26be44f190c2fa27e056ba on Ubuntu 18.04 and enabled the example-forum in .meteor/packages.

Any help appreciated.

[eric-burel]

Voting is handled in the vulcan:voting package. Help is welcome to fix this issue. We probably won't be able to maintain such packages in the future, voting looks simple but is actually a complex issue if you don't want people to be able to cheat and you want to handle concurrent calls.