gui: prepend broadcast_transaction errors with explanatory message

electrum/gui/kivy/main_window.py

@@ -937,8 +937,11 @@ class ElectrumWindow(App):
                     self.wallet.invoices.save()
                     self.update_tab('invoices')
             else:
-                msg = msg[:500] if msg else _('There was an error broadcasting the transaction.')
-                self.show_error(msg)
+                display_msg = _('The server returned an error when broadcasting the transaction.')
+                if msg:
+                    display_msg += '\n' + msg
+                display_msg = display_msg[:500]
+                self.show_error(display_msg)
 
         if self.network and self.network.is_connected():
             self.show_info(_('Sending'))

electrum/gui/qt/main_window.py

@@ -1690,7 +1690,10 @@ class ElectrumWindow(QMainWindow, MessageBoxMixin, PrintError):
                     self.invoice_list.update()
                     self.do_clear()
                 else:
-                    parent.show_error(msg)
+                    display_msg = _('The server returned an error when broadcasting the transaction.')
+                    if msg:
+                        display_msg += '\n' + msg
+                    parent.show_error(display_msg)
 
         WaitingDialog(self, _('Broadcasting transaction...'),
                       broadcast_thread, broadcast_done, self.on_error)

electrum/gui/stdio.py

@@ -206,7 +206,9 @@ class ElectrumGui:
         try:
             self.network.run_from_another_thread(self.network.broadcast_transaction(tx))
         except Exception as e:
-            print(repr(e))
+            display_msg = _('The server returned an error when broadcasting the transaction.')
+            display_msg += '\n' + repr(e)
+            print(display_msg)
         else:
             print(_('Payment sent.'))
             #self.do_clear()

electrum/gui/text.py

@@ -15,7 +15,7 @@ from electrum.storage import WalletStorage
 from electrum.network import NetworkParameters
 from electrum.interface import deserialize_server
 
-_ = lambda x:x
+_ = lambda x:x  # i18n
 
 
 class ElectrumGui:
@@ -370,7 +370,9 @@ class ElectrumGui:
         try:
             self.network.run_from_another_thread(self.network.broadcast_transaction(tx))
         except Exception as e:
-            self.show_message(repr(e))
+            display_msg = _('The server returned an error when broadcasting the transaction.')
+            display_msg += '\n' + repr(e)
+            self.show_message(display_msg)
         else:
             self.show_message(_('Payment sent.'))
             self.do_clear()

electrum/network.py

@@ -737,6 +737,7 @@ class Network(PrintError):
             timeout = self.get_network_timeout_seconds(NetworkTimeout.Urgent)
         out = await self.interface.session.send_request('blockchain.transaction.broadcast', [str(tx)], timeout=timeout)
         if out != tx.txid():
+            # note: this is untrusted input from the server
             raise Exception(out)
         return out  # txid