fix #2353: show error when sweeping dust

gui/qt/main_window.py

@@ -2306,9 +2306,10 @@ class ElectrumWindow(QMainWindow, MessageBoxMixin, PrintError):
         if not d.exec_():
             return
 
-        tx = self.wallet.sweep(get_pk(), self.network, self.config, get_address(), None)
-        if not tx:
-            self.show_message(_('No inputs found. (Note that inputs need to be confirmed)'))
+        try:
+            tx = self.wallet.sweep(get_pk(), self.network, self.config, get_address(), None)
+        except BaseException as e:
+            self.show_message(str(e))
             return
         self.warn_if_watching_only()
         self.show_transaction(tx)

lib/wallet.py

@@ -892,7 +892,7 @@ class Abstract_Wallet(PrintError):
             keypairs[pubkey] = privkey
 
         if not inputs:
-            return
+            raise BaseException(_('No inputs found. (Note that inputs need to be confirmed)'))
 
         total = sum(i.get('value') for i in inputs)
         if fee is None:
@@ -900,6 +900,12 @@ class Abstract_Wallet(PrintError):
             tx = Transaction.from_io(inputs, outputs)
             fee = self.estimate_fee(config, tx.estimated_size())
 
+        if total - fee < 0:
+            raise BaseException(_('Not enough funds on address.') + '\nTotal: %d satoshis\nFee: %d\nDust Threshold: %d'%(total, fee))
+
+        if total - fee < self.dust_threshold():
+            raise BaseException(_('Not enough funds on address.') + '\nTotal: %d satoshis\nFee: %d\nDust Threshold: %d'%(total, fee, self.dust_threshold()))
+
         outputs = [(TYPE_ADDRESS, recipient, total - fee)]
         tx = Transaction.from_io(inputs, outputs)
         tx.sign(keypairs)