340. Covenant conditional upon landlord's putting premises in repair.

The liability of the tenant to repair may be made conditional upon the landlord's first putting the premises in repair1, or upon his doing some other act, such as providing materials for repair2. In the former case, the complete performance of the condition by the landlord is essential to make the tenant liable for the repair of any part of the premises3; and, in the latter case, it is sufficient if the landlord is ready to supply the materials when required4. If the putting of the premises in repair or the provision of materials by the landlord is expressed