In May 1968, the Cannes Film Festival ground to a halt. Fifty years later, it's still sparking controversy

In the newly released comedy “Godard Mon Amour,” Michel Hazanavicius’ playful flashback to France in the fateful year of 1968, a young Jean-Luc Godard (played by Louis Garrel) marches with an enormous crowd in Paris. Alongside him is the critic and filmmaker Michel Cournot, whose “Les Gauloises...