Fix spurious AttributeError in bitcoin.rpc.Proxy()

Previously if the proxy connection couldn't be created for some reason, when
the proxy object was deleted a spurious AttributeError could be raised due to a
missing __conn attribute. Now only the actual exception will be raised.

Author: petertodd

bitcoin/rpc.py

@@ -83,6 +83,11 @@ def __init__(self,
                  btc_conf_file=None,
                  timeout=DEFAULT_HTTP_TIMEOUT):
 
+        # Create a dummy connection early on so if __init__() fails prior to
+        # __conn being created __del__() can detect the condition and handle it
+        # correctly.
+        self.__conn = None
+
         if service_url is None:
             # Figure out the path to the bitcoin.conf file
             if btc_conf_file is None:
@@ -181,7 +186,8 @@ def _get_response(self):
                           parse_float=decimal.Decimal)
 
     def __del__(self):
-        self.__conn.close()
+        if self.__conn is not None:
+            self.__conn.close()
 
 
 class RawProxy(BaseProxy):

release-notes.md

@@ -9,6 +9,10 @@ Breaking API changes:
 * The 'cooked' CScript iterator now returns OP_0 for the empty binary string
   rather than b''
 
+Bugfixes:
+
+* Fixed a spurious AttributeError when bitcoin.rpc.Proxy() fails.
+
 
 v0.6.1
 ======