Tenant's Right of Preference Against Subsequent Purchaser and Proof of Fraud

A property owner, having granted a right of preference to a tenant for the sale of the leased premises, sued the subsequent purchaser who had proceeded with the sale despite the tenant's demand to be substituted as the buyer, arguing that the purchaser was aware of the right of preference. The court ruled that the action for substitution against the third-party purchaser, based on the knowledge of the right of preference, is only admissible if the sale was executed in fraud of the right holder's claim, and since the lower court failed to establish such fraud, the claim for substitution was improperly granted, leading to the cassation of the decision.