network: change broadcast_transaction api

raise exceptions instead of weird return values
closes #4433

electrum/gui/kivy/main_window.py

@@ -887,9 +887,14 @@ class ElectrumWindow(App):
         Clock.schedule_once(lambda dt: on_success(tx))
 
     def _broadcast_thread(self, tx, on_complete):
-        ok, txid = self.network.run_from_another_thread(
-            self.network.broadcast_transaction(tx))
-        Clock.schedule_once(lambda dt: on_complete(ok, txid))
+
+        try:
+            self.network.run_from_another_thread(self.network.broadcast_transaction(tx))
+        except Exception as e:
+            ok, msg = False, repr(e)
+        else:
+            ok, msg = True, tx.txid()
+        Clock.schedule_once(lambda dt: on_complete(ok, msg))
 
     def broadcast(self, tx, pr=None):
         def on_complete(ok, msg):

electrum/gui/qt/main_window.py

@@ -1639,8 +1639,12 @@ class ElectrumWindow(QMainWindow, MessageBoxMixin, PrintError):
             if pr and pr.has_expired():
                 self.payment_request = None
                 return False, _("Payment request has expired")
-            status, msg = self.network.run_from_another_thread(
-                self.network.broadcast_transaction(tx))
+            try:
+                self.network.run_from_another_thread(self.network.broadcast_transaction(tx))
+            except Exception as e:
+                status, msg = False, repr(e)
+            else:
+                status, msg = True, tx.txid()
             if pr and status is True:
                 self.invoices.set_paid(pr, tx.txid())
                 self.invoices.save()

electrum/gui/stdio.py

@@ -203,15 +203,14 @@ class ElectrumGui:
             self.wallet.labels[tx.txid()] = self.str_description
 
         print(_("Please wait..."))
-        status, msg = self.network.run_from_another_thread(
-            self.network.broadcast_transaction(tx))
-
-        if status:
+        try:
+            self.network.run_from_another_thread(self.network.broadcast_transaction(tx))
+        except Exception as e:
+            print(repr(e))
+        else:
             print(_('Payment sent.'))
             #self.do_clear()
             #self.update_contacts_tab()
-        else:
-            print(_('Error'))
 
     def network_dialog(self):
         print("use 'electrum setconfig server/proxy' to change your network settings")

electrum/gui/text.py

@@ -367,16 +367,14 @@ class ElectrumGui:
             self.wallet.labels[tx.txid()] = self.str_description
 
         self.show_message(_("Please wait..."), getchar=False)
-        status, msg = self.network.run_from_another_thread(
-            self.network.broadcast_transaction(tx))
-
-        if status:
+        try:
+            self.network.run_from_another_thread(self.network.broadcast_transaction(tx))
+        except Exception as e:
+            self.show_message(repr(e))
+        else:
             self.show_message(_('Payment sent.'))
             self.do_clear()
             #self.update_contacts_tab()
-        else:
-            self.show_message(_('Error'))
-
 
     def show_message(self, message, getchar = True):
         w = self.w

electrum/network.py

@@ -676,16 +676,10 @@ class Network(PrintError):
 
     @best_effort_reliable
     async def broadcast_transaction(self, tx, timeout=10):
-        try:
-            out = await self.interface.session.send_request('blockchain.transaction.broadcast', [str(tx)], timeout=timeout)
-        except RequestTimedOut as e:
-            return False, "error: operation timed out"
-        except Exception as e:
-            return False, "error: " + str(e)
-
+        out = await self.interface.session.send_request('blockchain.transaction.broadcast', [str(tx)], timeout=timeout)
         if out != tx.txid():
-            return False, "error: " + out
-        return True, out
+            raise Exception(out)
+        return out  # txid
 
     @best_effort_reliable
     async def request_chunk(self, height, tip=None, *, can_return_early=False):