Electrum plugin: Restore previous oneserver setting when the plugin is disabled

To prevent users from inadvertently connecting to public Electrum servers with this setting still on.

Resolves #23

Author: shesek

CHANGELOG.md

@@ -1,5 +1,10 @@
 # Changelog
 
+## Unreleased
+
+- Electrum plugin: Restore the previous `oneserver` setting when the plugin is disabled,
+  to prevent users from inadvertently connecting to public Electrum servers with this setting still on.
+
 ## 0.1.1 - 2020-05-27
 
 - Make bwt available as an Electrum plugin! 💥

contrib/electrum-plugin/bwt.py

@@ -36,6 +36,9 @@ def __init__(self, parent, config, name):
         self.poll_interval = config.get('bwt_poll_interval', 5)
         self.verbose = config.get('bwt_verbose', 0)
 
+        if config.get('bwt_was_oneserver') is None:
+            config.set_key('bwt_was_oneserver', config.get('oneserver'))
+
         self.start()
 
     def start(self):
@@ -119,6 +122,12 @@ def close(self):
         BasePlugin.close(self)
         self.stop()
 
+        # restore the user's previous oneserver setting when the plugin is disabled
+        was_oneserver = self.config.get('bwt_was_oneserver')
+        if was_oneserver is not None:
+          self.config.set_key('oneserver', was_oneserver)
+          self.config.set_key('bwt_was_oneserver', None)
+
     def handle_log(self, level, pkg, msg):
         if msg.startswith('Electrum RPC server running'):
             self.set_server()