handle failure to retrieve broadcasted transaction from mempool, allow retry

src/main/java/com/sparrowwallet/sparrow/transaction/HeadersController.java

@@ -815,6 +815,7 @@ public class HeadersController extends TransactionFormController implements Init
                 transactionMempoolService = new ElectrumServer.TransactionMempoolService(headersForm.getSigningWallet(), headersForm.getTransaction().getTxId(), headersForm.getSigningWalletNodes());
                 transactionMempoolService.setDelay(Duration.seconds(3));
                 transactionMempoolService.setPeriod(Duration.seconds(10));
+                transactionMempoolService.setRestartOnFailure(false);
                 transactionMempoolService.setOnSucceeded(mempoolWorkerStateEvent -> {
                     Set<String> scriptHashes = transactionMempoolService.getValue();
                     if(!scriptHashes.isEmpty()) {
@@ -829,6 +830,13 @@ public class HeadersController extends TransactionFormController implements Init
                         broadcastButton.setDisable(false);
                     }
                 });
+                transactionMempoolService.setOnFailed(mempoolWorkerStateEvent -> {
+                    transactionMempoolService.cancel();
+                    broadcastProgressBar.setProgress(0);
+                    log.error("Timeout searching for broadcasted transaction");
+                    AppServices.showErrorDialog("Timeout searching for broadcasted transaction", "The transaction was broadcast but the server did not indicate it had entered the mempool. It is safe to try broadcasting again.");
+                    broadcastButton.setDisable(false);
+                });
                 transactionMempoolService.start();
             } else {
                 Sha256Hash txid = headersForm.getTransaction().getTxId();