feat: cannot call setRepaid more than once

Author: maxencerb

src/request/Request.sol

@@ -172,7 +172,9 @@ contract Request is IRequest, OfferReceiver, VaultController, Initializable, Own
   /// @dev Only callable by the owner. Once called, `canWithdraw()` returns true and users
   ///      can redeem their PT/YT tokens for the underlying asset. This action is irreversible.
   ///      Emits a {Repaid} event.
+  /// @custom:reverts If the request has already been repaid
   function setRepaid() external onlyOwner {
+    if (_canWithdraw()) revert AlreadyRepaid();
     _requestStorage().repaid = true;
     emit Repaid();
   }

test/request/Request.t.sol

@@ -364,6 +364,15 @@ contract RequestTest is Test {
     request.setRepaid();
   }
 
+  function test_setRepaid_cannotCallTwice() public {
+    vm.prank(owner);
+    request.setRepaid();
+
+    vm.prank(owner);
+    vm.expectRevert(AlreadyRepaid.selector);
+    request.setRepaid();
+  }
+
   /*´:°•.°+.*•´.*:˚.°*.˚•´.°:°•.°•.*•´.*:˚.°*.˚•´.°:°•.°+.*•´.*:*/
   /*                 INTEGRATION TESTS                           */
   /*.•°:°.´+˚.*°.˚:*.´•*.+°.•°:´*.´•*.•°.•°:°.´:•˚°.*°.˚:*.´+°.•*/