Try to query wsdl type/method from vim25 namespace first when namespace is unknown.

Some type, in this case 'Task' is not defined in the specified namespace(urn:nfc). In such case, the deserializer will have to guess the namespace by interate namesapce in the _wsdlTypeMapNSs. 'Task' exists in multiple namespaces. In python2, the order in the map is fixed and vim25 is always tried first, but in python3 the order of the set is random. If wrong namespace is returned, the xml parser will fail later on.

pyVmomi/VmomiSupport.py

@@ -1049,9 +1049,15 @@ class UnknownWsdlTypeError(KeyError):
 # @return type if found in any one of the name spaces else throws KeyError
 def GuessWsdlType(name):
    with _lazyLock:
-      # Because the types are lazily loaded, if some name is present
-      # in multiple namespaces, we will load the first type that we
-      # encounter and return it.
+      # Some types may exist in multiple namespaces, and returning
+      # the wrong one will cause a deserialization error.
+      # Since in python3 the order of entries in set is not deterministic,
+      # we will try to get the type from vim25 namespace first.
+      try:
+         return GetWsdlType(XMLNS_VMODL_BASE, name)
+      except KeyError:
+         pass
+
       for ns in _wsdlTypeMapNSs:
          try:
             return GetWsdlType(ns, name)
@@ -1242,6 +1248,15 @@ def GetWsdlMethod(ns, wsdlName):
 # KeyError
 def GuessWsdlMethod(name):
    with _lazyLock:
+      # Some methods may exist in multiple namespaces, and returning
+      # the wrong one will cause a deserialization error.
+      # Since in python3 the order of entries in set is not deterministic,
+      # we will try to get the method from vim25 namespace first.
+      try:
+         return GetWsdlMethod(XMLNS_VMODL_BASE, name)
+      except KeyError:
+         pass
+
       for ns in _wsdlMethodNSs:
          try:
             return GetWsdlMethod(ns, name)