Umbrella Coup (1980)

Grégoire Lecomte, the unlucky actor anxious to find a “real job”, goes to take a screen test for a role of a killer, but gets to mafiosi by mistake. He takes their don for a producer, and they mistake him for a hitman with whom they had an appointment. Deluded Lecomte signs contract with them. He is supposed to kill gun dealer Otto Krampe at his birthday party in Saint-Tropez by piercing him with a cap of the umbrella with a built-in syringe with potassium cyanide. Lecomte is not aware that it has to be a real murder.
Gérard Oury
Pierre Richard, Valérie Mairesse, Christine Murillo, Gérard Jugnot, Gordon Mitchell, Georges Anderson, Roger Carel, Gert Fröbe, Maurice Risch, Dominique Lavanant, Axelle Abbadie, Yaseen Khan, Didier Sauvegrain, Mike Marshall, Vittorio Caprioli, Patrick Lecocq, Robert Dalban, Tiberio Murgia
tt0080565