Fix trade_preimage, withdraw if max and force_min_relay_fee are set #1037

mm2src/coins/utxo/utxo_common.rs

@@ -426,10 +426,10 @@ where
                         if let ActualTxFee::Dynamic(ref f) = coin_tx_fee {
                             tx_fee += (f * P2PKH_OUTPUT_LEN) / KILO_BYTE;
                         }
-                        if let Some(min_relay) = min_relay_fee {
-                            if tx_fee < min_relay {
-                                tx_fee = min_relay;
-                            }
+                    }
+                    if let Some(min_relay) = min_relay_fee {
+                        if tx_fee < min_relay {
+                            tx_fee = min_relay;
                         }
                     }
                     break;

mm2src/coins/utxo/utxo_tests.rs

@@ -1105,6 +1105,52 @@ fn test_generate_transaction_relay_fee_is_used_when_dynamic_fee_is_lower() {
     assert!(unsafe { GET_RELAY_FEE_CALLED });
 }
 
+#[test]
+#[cfg(not(target_arch = "wasm32"))]
+// https://github.com/KomodoPlatform/atomicDEX-API/issues/1037
+fn test_generate_transaction_relay_fee_is_used_when_dynamic_fee_is_lower_and_deduct_from_output() {
+    let client = NativeClientImpl::default();
+
+    static mut GET_RELAY_FEE_CALLED: bool = false;
+    NativeClient::get_relay_fee.mock_safe(|_| {
+        unsafe { GET_RELAY_FEE_CALLED = true };
+        MockResult::Return(Box::new(futures01::future::ok("1.0".parse().unwrap())))
+    });
+    let client = UtxoRpcClientEnum::Native(NativeClient(Arc::new(client)));
+    let mut coin = utxo_coin_fields_for_test(client, None, false);
+    coin.conf.force_min_relay_fee = true;
+    let coin = utxo_coin_from_fields(coin);
+    let unspents = vec![UnspentInfo {
+        value: 1000000000,
+        outpoint: OutPoint::default(),
+        height: Default::default(),
+    }];
+
+    let outputs = vec![TransactionOutput {
+        script_pubkey: vec![].into(),
+        value: 1000000000,
+    }];
+
+    let fut = coin.generate_transaction(
+        unspents,
+        outputs,
+        FeePolicy::DeductFromOutput(0),
+        Some(ActualTxFee::Dynamic(100)),
+        None,
+    );
+    let generated = block_on(fut).unwrap();
+    assert_eq!(generated.0.outputs.len(), 1);
+    // `output (= 10.0) - fee_amount (= 1.0)`
+    assert_eq!(generated.0.outputs[0].value, 900000000);
+
+    // generated transaction fee must be equal to relay fee if calculated dynamic fee is lower than relay
+    assert_eq!(generated.1.fee_amount, 100000000);
+    assert_eq!(generated.1.unused_change, None);
+    assert_eq!(generated.1.received_by_me, 0);
+    assert_eq!(generated.1.spent_by_me, 1000000000);
+    assert!(unsafe { GET_RELAY_FEE_CALLED });
+}
+
 #[test]
 #[cfg(not(target_arch = "wasm32"))]
 // https://github.com/KomodoPlatform/atomicDEX-API/issues/617