bitbake: Fix default function parameter assignment to a list

With python you should not assign a list as the default value of a
function parameter - because a list is mutable, the result will be that
the first time a value is passed it will actually modify the default.
Reference:

http://docs.python-guide.org/en/latest/writing/gotchas/#mutable-default-arguments

(Bitbake rev: 7859f7388f2e3f675d0e1527cfde18625f36f637)

Signed-off-by: Paul Eggleton <paul.eggleton@linux.intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

bitbake/lib/bb/server/process.py

@@ -124,8 +124,10 @@ class ProcessServer(Process, BaseImplServer):
         self.command_channel.close()
         self.cooker.shutdown(True)
 
-    def idle_commands(self, delay, fds = []):
+    def idle_commands(self, delay, fds=None):
         nextsleep = delay
+        if not fds:
+            fds = []
 
         for function, data in self._idlefuns.items():
             try:

bitbake/lib/bb/server/xmlrpc.py

@@ -281,12 +281,15 @@ class XMLRPCServer(SimpleXMLRPCServer, BaseImplServer):
         self.connection_token = token
 
 class BitBakeXMLRPCServerConnection(BitBakeBaseServerConnection):
-    def __init__(self, serverImpl, clientinfo=("localhost", 0), observer_only = False, featureset = []):
+    def __init__(self, serverImpl, clientinfo=("localhost", 0), observer_only = False, featureset = None):
         self.connection, self.transport = _create_server(serverImpl.host, serverImpl.port)
         self.clientinfo = clientinfo
         self.serverImpl = serverImpl
         self.observer_only = observer_only
-        self.featureset = featureset
+        if featureset:
+            self.featureset = featureset
+        else:
+            self.featureset = []
 
     def connect(self, token = None):
         if token is None: