new test case

src/test/app/NFTokenBurn_test.cpp

@@ -612,6 +612,53 @@ class NFTokenBurn_test : public beast::unit_test::suite
             BEAST_EXPECT(ownerCount(env, becky) == 0);
         }
 
+        // Test that up to 499 buy/sell offers will be removed when NFT is burned
+        // after fixUnburnableNFToken is enabled.
+        // This is to test that we can successfully remove all offers 
+        // if the number of offers is less than 500.
+        {
+            Env env{*this, features | fixUnburnableNFToken};
+
+            Account const alice("alice");
+            env.fund(XRP(1000), alice);
+            env.close();
+
+            // We create 498 buy offers and 1 sell offers.
+            // When the token is burned, all of the 498 buy offers should be removed, and the sell offers is removed.
+            // In total, 499 offers are removed
+            std::vector<uint256> offerIndexes;
+            auto const nftokenID = createNftAndOffers(env, alice, offerIndexes, maxDeletableTokenOfferEntries - 2);
+
+            // Verify all offers are present in the ledger.
+            for (uint256 const& offerIndex : offerIndexes)
+            {
+                BEAST_EXPECT(env.le(keylet::nftoffer(offerIndex)));
+            }
+
+            // Create sell offer
+            uint256 const aliceOfferIndex =
+                keylet::nftoffer(alice, env.seq(alice)).key;
+            env(token::createOffer(alice, nftokenID, drops(1)),
+                txflags(tfSellNFToken));
+            env.close();
+
+            env(token::burn(alice, nftokenID));
+            env.close();
+
+            // Burning the token should remove all 498 buy-offers from the ledger.
+            for (uint256 const& offerIndex : offerIndexes)
+            {
+                BEAST_EXPECT(!env.le(keylet::nftoffer(offerIndex)));  
+            }
+
+            // Burning the token should also remove the 499th offer that alice created
+            // And leave out the additional sell offer
+            BEAST_EXPECT(!env.le(keylet::nftoffer(aliceOfferIndex)));
+
+            // alice should have ownerCounts of one.
+            BEAST_EXPECT(ownerCount(env, alice) == 0);
+        }
+
         // Test that up to 500 buy offers are removed when NFT is burned
         // after fixUnburnableNFToken is enabled
         {