Result computations fail when ballot box contains only 1 ballot

[Nitorac]

I encoutered an issue with Belenios branch stable (last commit in branch : d0edd18) when I want to compute the results.

Environment

Clean install of Belenios from stable branch on Debian, using the demo folder with the run-server.sh.

Description

I create an election with 1 or more voters, only one of them submit a ballot.
The ballot box must contain only 1 ballot submitted.
Close the election and try to compute the results.

Expected behavior

When clicking the button "Compute the results", Belenios should redirect on results page.

Actual behavior

When clicking the button "Compute the results", I have a response with status code 500 and body : Error: (Invalid_argument "Cannot compute result")

Tests

I have tested this behavior with :

• 1 voters with 1 ballot in the ballot box -> Bug happens
• 3 voters with 1 ballot in the ballot box -> Bug happens
• 3 voters with 2 ballots in the ballot box -> No bug happens

Screens

I am open to any precision if needed !

[glondu]

Thank you for this bug report! It should be fixed now.