Check against dust threshold for single joins

scripts/joinmarket-qt.py

@@ -66,6 +66,7 @@ JM_CORE_VERSION = '0.6.1'
 JM_GUI_VERSION = '11'
 
 from jmbase import get_log
+from jmbase.support import DUST_THRESHOLD
 from jmclient import load_program_config, get_network, update_persist_config,\
     open_test_wallet_maybe, get_wallet_path, get_p2sh_vbyte, get_p2pk_vbyte,\
     jm_single, validate_address, weighted_order_choose, Taker,\
@@ -109,6 +110,22 @@ def checkAddress(parent, addr):
                        mbtype='warn',
                        title="Error")
 
+
+def checkAmount(parent, amount_str):
+    if not amount_str:
+        return False
+    amount_sat = btc.amount_to_sat(amount_str)
+    if amount_sat < DUST_THRESHOLD:
+        JMQtMessageBox(parent,
+                       "Amount " + btc.amount_to_str(amount_sat) +
+                       " is below dust threshold " +
+                       btc.amount_to_str(DUST_THRESHOLD) + ".",
+                       mbtype='warn',
+                       title="Error")
+        return False
+    return True
+
+
 def getSettingsWidgets():
     results = []
     sN = ['Recipient address', 'Number of counterparties', 'Mixdepth',
@@ -609,11 +626,14 @@ class SpendTab(QWidget):
         if not self.validateSettings():
             return
         destaddr = str(self.widgets[0][1].text())
-        #convert from bitcoins (enforced by QDoubleValidator) to satoshis
-        btc_amount_str = self.widgets[3][1].text()
-        amount = btc.amount_to_sat(btc_amount_str)
         makercount = int(self.widgets[1][1].text())
         mixdepth = int(self.widgets[2][1].text())
+        btc_amount_str = self.widgets[3][1].text()
+        # for coinjoin sends no point to send below dust threshold, likely
+        # there will be no makers for such amount.
+        if makercount != 0 and not checkAmount(self, btc_amount_str):
+            return
+        amount = btc.amount_to_sat(btc_amount_str)
         if makercount == 0:
             try:
                 txid = direct_send(mainWindow.wallet_service, amount, mixdepth,

scripts/sendpayment.py

@@ -18,7 +18,7 @@ from jmclient import Taker, P2EPTaker, load_program_config, get_schedule,\
     get_sendpayment_parser, get_max_cj_fee_values, check_regtest
 from twisted.python.log import startLogging
 from jmbase.support import get_log, set_logging_level, jmprint, \
-    EXIT_FAILURE, EXIT_ARGERROR
+    EXIT_FAILURE, EXIT_ARGERROR, DUST_THRESHOLD
 
 import jmbitcoin as btc
 
@@ -72,6 +72,11 @@ def main():
         if not addr_valid:
             jmprint('ERROR: Address invalid. ' + errormsg, "error")
             sys.exit(EXIT_ARGERROR)
+        if amount < DUST_THRESHOLD:
+            jmprint('ERROR: Amount ' + btc.amount_to_str(amount) +
+                ' is below dust threshold ' +
+                btc.amount_to_str(DUST_THRESHOLD) + '.', "error")
+            sys.exit(EXIT_ARGERROR)
         schedule = [[options.mixdepth, amount, options.makercount,
                      destaddr, 0.0, NO_ROUNDING, 0]]
     else: