Use checkpoint to verify pre-checkpoint headers from the server, remo…

…ving the need for complete header synchronisation. Now only post-checkpoint headers are synchronised, and pre-checkpoint headers are fetched primarily to aid the verifier. This commit incorporates selected changes from Electrum modified to support the different checkpoint models. If the hardcoded checkpoint heights in `networks.py` are replaced with None, then the application will fetch at least three checkpoints from different servers and compare them, using those to proceed. This can be used to get obtain the a recent checkpoint for release, and won't be used unless specifically activated, as this commit comes with the initial hard-coded checkpoint heights.

gui/kivy/main_window.py

@@ -806,7 +806,7 @@ def _sign_tx(self, tx, password, on_success, on_failure):
         Clock.schedule_once(lambda dt: on_success(tx))
 
     def _broadcast_thread(self, tx, on_complete):
-        ok, txid = self.network.broadcast(tx)
+        ok, txid = self.network.broadcast_transaction(tx)
         Clock.schedule_once(lambda dt: on_complete(ok, txid))
 
     def broadcast(self, tx, pr=None):

gui/qt/main_window.py

@@ -1545,7 +1545,7 @@ def broadcast_thread():
             if pr and pr.has_expired():
                 self.payment_request = None
                 return False, _("Payment request has expired")
-            status, msg =  self.network.broadcast(tx)
+            status, msg =  self.network.broadcast_transaction(tx)
             if pr and status is True:
                 self.invoices.set_paid(pr, tx.txid())
                 self.invoices.save()

gui/qt/network_dialog.py

@@ -108,7 +108,7 @@ def update(self, network):
             if n_chains >1:
                 x = QTreeWidgetItem([name + '@%d'%b.get_checkpoint(), '%d'%b.height()])
                 x.setData(0, Qt.UserRole, 1)
-                x.setData(1, Qt.UserRole, b.checkpoint)
+                x.setData(1, Qt.UserRole, b.base_height)
             else:
                 x = self
             for i in items:

gui/stdio.py

@@ -199,7 +199,7 @@ def do_send(self):
             self.wallet.labels[tx.txid()] = self.str_description
 
         print(_("Please wait..."))
-        status, msg = self.network.broadcast(tx)
+        status, msg = self.network.broadcast_transaction(tx)
 
         if status:
             print(_('Payment sent.'))

gui/text.py

@@ -350,7 +350,7 @@ def do_send(self):
             self.wallet.labels[tx.txid()] = self.str_description
 
         self.show_message(_("Please wait..."), getchar=False)
-        status, msg = self.network.broadcast(tx)
+        status, msg = self.network.broadcast_transaction(tx)
 
         if status:
             self.show_message(_('Payment sent.'))

ios/ElectronCash/electroncash_gui/ios_native/gui.py

@@ -1712,7 +1712,7 @@ def broadcast_thread(): # non-GUI thread
             #if pr and pr.has_expired():
             #    self.payment_request = None
             #    return False, _("Payment request has expired")
-            status, msg =  self.daemon.network.broadcast(tx)
+            status, msg =  self.daemon.network.broadcast_transaction(tx)
             #if pr and status is True:
             #    self.invoices.set_paid(pr, tx.txid())
             #    self.invoices.save()

ios/ElectronCash/electroncash_gui/ios_native/network_dialog.py

@@ -278,7 +278,7 @@ def refresh(self) -> None:
             extraData = None
             if n_chains > 1:
                 secHeader = "(" + (name + '@%d'%b.get_checkpoint()) + ") " + _("Host") + ", " + _("Height")
-                extraData = [ False, b.checkpoint, name ]
+                extraData = [ False, b.base_height, name ]
             for i in items:
                 star = ' *' if i == network.interface else ''
                 extraData = [True, i.server, ''] #if n_chains <= 1 else extraData