Do not post invalid price ask if not match

programs/openbook-v2/src/state/orderbook/book.rs

@@ -162,18 +162,22 @@ impl<'a> Orderbook<'a> {
 
             if !side.is_price_within_limit(best_opposing_price, price_lots) {
                 break;
-            } else if post_only {
+            }
+            if post_only {
                 msg!("Order could not be placed due to PostOnly");
                 post_target = None;
                 break; // return silently to not fail other instructions in tx
-            } else if limit == 0 {
+            }
+            if limit == 0 {
                 msg!("Order matching limit reached");
                 post_target = None;
                 break;
             }
 
             let max_match_by_quote = remaining_quote_lots / best_opposing_price;
+            // Do not post orders in the book due to bad pricing and negative spread
             if max_match_by_quote == 0 {
+                post_target = None;
                 break;
             }
 

programs/openbook-v2/tests/cases/test_take_order.rs

@@ -288,3 +288,82 @@ async fn test_take_bid_order() -> Result<(), TransportError> {
 
     Ok(())
 }
+
+#[tokio::test]
+async fn test_negative_spread_ask() -> Result<(), TransportError> {
+    let TestInitialize {
+        context,
+        owner,
+        owner_token_0,
+        owner_token_1,
+        market,
+        market_base_vault,
+        market_quote_vault,
+        account_1,
+        account_2,
+        ..
+    } = TestContext::new_with_market(TestNewMarketInitialize {
+        quote_lot_size: 100,
+        base_lot_size: 1_000_000_000,
+        ..TestNewMarketInitialize::default()
+    })
+    .await?;
+    let solana = &context.solana.clone();
+
+    send_tx(
+        solana,
+        PlaceOrderInstruction {
+            open_orders_account: account_1,
+            open_orders_admin: None,
+            market,
+            signer: owner,
+            user_token_account: owner_token_1,
+            market_vault: market_quote_vault,
+            side: Side::Bid,
+            price_lots: 10_000,     // $1
+            max_base_lots: 1000000, // wahtever
+            max_quote_lots_including_fees: 10_000,
+            client_order_id: 1,
+            expiry_timestamp: 0,
+            order_type: PlaceOrderType::Limit,
+            self_trade_behavior: SelfTradeBehavior::default(),
+            remainings: vec![],
+        },
+    )
+    .await
+    .unwrap();
+
+    // This order doesn't take any due max_quote_lots_including_fees but it's also don't post in on the book
+    send_tx(
+        solana,
+        PlaceOrderInstruction {
+            open_orders_account: account_2,
+            open_orders_admin: None,
+            market,
+            signer: owner,
+            user_token_account: owner_token_0,
+            market_vault: market_base_vault,
+            side: Side::Ask,
+            price_lots: 7_500,
+            max_base_lots: 1,
+            max_quote_lots_including_fees: 7_500,
+            client_order_id: 25,
+            expiry_timestamp: 0,
+            order_type: PlaceOrderType::Limit,
+            self_trade_behavior: SelfTradeBehavior::AbortTransaction,
+            remainings: vec![],
+        },
+    )
+    .await
+    .unwrap();
+
+    let position = solana
+        .get_account::<OpenOrdersAccount>(account_2)
+        .await
+        .position;
+
+    assert_eq!(position.asks_base_lots, 0);
+    assert_eq!(position.bids_base_lots, 0);
+
+    Ok(())
+}