various minor fixes

src/main/java/com/sparrowwallet/sparrow/AppController.java

@@ -331,7 +331,7 @@ public class AppController implements Initializable {
         sendToMany.disableProperty().bind(exportWallet.disableProperty());
         findMixingPartner.setDisable(true);
         AppServices.onlineProperty().addListener((observable, oldValue, newValue) -> {
-            findMixingPartner.setDisable(exportWallet.isDisable() || !SorobanServices.canWalletMix(getSelectedWalletForm().getWallet()) || !newValue);
+            findMixingPartner.setDisable(exportWallet.isDisable() || getSelectedWalletForm() == null || !SorobanServices.canWalletMix(getSelectedWalletForm().getWallet()) || !newValue);
         });
 
         setServerType(Config.get().getServerType());
@@ -1495,6 +1495,7 @@ public class AppController implements Initializable {
 
     public WalletForm getSelectedWalletForm() {
         Tab selectedTab = tabs.getSelectionModel().getSelectedItem();
+        if(selectedTab != null) {
             TabData tabData = (TabData)selectedTab.getUserData();
             if(tabData instanceof WalletTabData) {
                 TabPane subTabs = (TabPane)selectedTab.getContent();
@@ -1502,6 +1503,7 @@ public class AppController implements Initializable {
                 WalletTabData subWalletTabData = (WalletTabData)selectedSubTab.getUserData();
                 return subWalletTabData.getWalletForm();
             }
+        }
 
         return null;
     }

src/main/java/com/sparrowwallet/sparrow/control/TransactionDiagram.java

@@ -507,7 +507,7 @@ public class TransactionDiagram extends GridPane {
             recipientTooltip.setShowDelay(new Duration(TOOLTIP_SHOW_DELAY));
             recipientTooltip.setShowDuration(Duration.INDEFINITE);
             recipientLabel.setTooltip(recipientTooltip);
-            outputNodes.add(new OutputNode(recipientLabel, payment.getAddress()));
+            outputNodes.add(new OutputNode(recipientLabel, payment.getAddress(), payment.getAmount()));
         }
 
         for(Map.Entry<WalletNode, Long> changeEntry : walletTx.getChangeMap().entrySet()) {
@@ -543,7 +543,7 @@ public class TransactionDiagram extends GridPane {
                 actionBox.getChildren().add(replaceChangeLabel);
             }
 
-            outputNodes.add(new OutputNode(actionBox, changeAddress));
+            outputNodes.add(new OutputNode(actionBox, changeAddress, changeEntry.getValue()));
         }
 
         if(isFinal()) {
@@ -634,7 +634,7 @@ public class TransactionDiagram extends GridPane {
         if(payment.getType() == Payment.Type.WHIRLPOOL_FEE) {
             return "Whirlpool Fee";
         } else if(walletTx.isPremixSend(payment)) {
-            int premixIndex = getOutputIndex(payment.getAddress()) - 2;
+            int premixIndex = getOutputIndex(payment.getAddress(), payment.getAmount()) - 2;
             return "Premix #" + premixIndex;
         } else if(walletTx.isBadbankSend(payment)) {
             return "Badbank Change";
@@ -643,8 +643,8 @@ public class TransactionDiagram extends GridPane {
         return null;
     }
 
-    private int getOutputIndex(Address address) {
-        return walletTx.getTransaction().getOutputs().stream().filter(txOutput -> address.equals(txOutput.getScript().getToAddress())).mapToInt(TransactionOutput::getIndex).findFirst().orElseThrow();
+    private int getOutputIndex(Address address, long amount) {
+        return walletTx.getTransaction().getOutputs().stream().filter(txOutput -> address.equals(txOutput.getScript().getToAddress()) && txOutput.getValue() == amount).mapToInt(TransactionOutput::getIndex).findFirst().orElseThrow();
     }
 
     private Wallet getToWallet(Payment payment) {
@@ -949,16 +949,18 @@ public class TransactionDiagram extends GridPane {
     private class OutputNode implements Comparable<OutputNode> {
         public Node outputLabel;
         public Address address;
+        public long amount;
 
-        public OutputNode(Node outputLabel, Address address) {
+        public OutputNode(Node outputLabel, Address address, long amount) {
             this.outputLabel = outputLabel;
             this.address = address;
+            this.amount = amount;
         }
 
         @Override
         public int compareTo(TransactionDiagram.OutputNode o) {
             try {
-                return getOutputIndex(address) - getOutputIndex(o.address);
+                return getOutputIndex(address, amount) - getOutputIndex(o.address, o.amount);
             } catch(Exception e) {
                 return 0;
             }

src/main/java/com/sparrowwallet/sparrow/wallet/SendController.java

@@ -1288,7 +1288,7 @@ public class SendController extends WalletFormController implements Initializabl
             whirlpoolProperty.set(event.getPool());
             updateTransaction(event.getPayments() == null || event.getPayments().stream().anyMatch(Payment::isSendMax));
 
-            boolean isWhirlpoolPremix = (event.getPayments() != null && event.getPayments().stream().anyMatch(payment -> payment.getType().equals(Payment.Type.WHIRLPOOL_FEE)));
+            boolean isWhirlpoolPremix = (event.getPool() != null);
             setInputFieldsDisabled(isWhirlpoolPremix);
             premixButton.setVisible(isWhirlpoolPremix);
             premixButton.setDefaultButton(isWhirlpoolPremix);

src/main/java/com/sparrowwallet/sparrow/wallet/UtxosController.java

@@ -328,6 +328,7 @@ public class UtxosController extends WalletFormController implements Initializab
         Wallet badbankWallet = masterWallet.getChildWallet(StandardAccount.WHIRLPOOL_BADBANK);
 
         List<Payment> payments = new ArrayList<>();
+        if(tx0Preview.getTx0Data().getFeeAddress() != null) {
             try {
                 Address whirlpoolFeeAddress = Address.fromString(tx0Preview.getTx0Data().getFeeAddress());
                 Payment whirlpoolFeePayment = new Payment(whirlpoolFeeAddress, "Whirlpool Fee", tx0Preview.getFeeValue(), false);
@@ -336,6 +337,7 @@ public class UtxosController extends WalletFormController implements Initializab
             } catch(InvalidAddressException e) {
                 throw new IllegalStateException("Cannot parse whirlpool fee address " + tx0Preview.getTx0Data().getFeeAddress(), e);
             }
+        }
 
         WalletNode badbankNode = badbankWallet.getFreshNode(KeyPurpose.RECEIVE);
         Payment changePayment = new Payment(badbankWallet.getAddress(badbankNode), "Badbank Change", tx0Preview.getChangeValue(), false);