Abort single join early if maker count below minimum_makers

scripts/joinmarket-qt.py

@@ -629,11 +629,20 @@ class SpendTab(QWidget):
         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
+        if makercount != 0:
+            # for coinjoin sends no point to send below dust threshold,
             # there will be no makers for such amount.
-        if (makercount != 0 and btc_amount_str != '0' and
+            if (btc_amount_str != '0' and
                 not checkAmount(self, btc_amount_str)):
                 return
+            if makercount < jm_single().config.getint(
+                "POLICY", "minimum_makers"):
+                JMQtMessageBox(self, "Number of counterparties (" + str(
+                    makercount) + ") below minimum_makers (" + str(
+                    jm_single().config.getint("POLICY", "minimum_makers")) +
+                    ") in configuration.",
+                    title="Error", mbtype="warn")
+                return
         amount = btc.amount_to_sat(btc_amount_str)
         if makercount == 0:
             try:

scripts/sendpayment.py

@@ -77,6 +77,14 @@ def main():
                 ' is below dust threshold ' +
                 btc.amount_to_str(DUST_THRESHOLD) + '.', "error")
             sys.exit(EXIT_ARGERROR)
+        if (options.makercount != 0 and
+            options.makercount < jm_single().config.getint(
+            "POLICY", "minimum_makers")):
+            jmprint('ERROR: Maker count ' + str(options.makercount) +
+                ' below minimum_makers (' + str(jm_single().config.getint(
+                "POLICY", "minimum_makers")) + ') in joinmarket.cfg.',
+                "error")
+            sys.exit(EXIT_ARGERROR)
         schedule = [[options.mixdepth, amount, options.makercount,
                      destaddr, 0.0, NO_ROUNDING, 0]]
     else: