fixed Bits.clone()/subtype()

2 files changed, 12 insertions, 9 deletions

diff --git a/CHANGES.txt b/CHANGES.txt
index 5fbe9d3e..6ed56337 100644
--- a/CHANGES.txt
+++ b/CHANGES.txt
@@ -21,6 +21,7 @@ Revision 4.3.10, released 2017-10-XX
 - Fixed multiple bugs in SNMP table indices rendering, especially
   the InetAddressIPv6 type which was severely broken.
 - Fixed crashing Bits.prettyPrint() implementation
+- Fixed crashing Bits.clone()/subtype() implementation
 - Fixed leaking exceptions bubbling up from the asyncio and Twisted adapters
 
 Revision 4.3.9, released 2017-07-26
diff --git a/pysnmp/proto/rfc1902.py b/pysnmp/proto/rfc1902.py
index 805132c9..60e31930 100644
--- a/pysnmp/proto/rfc1902.py
+++ b/pysnmp/proto/rfc1902.py
@@ -609,31 +609,33 @@ class Bits(OctetString):
 
     def clone(self, *args, **kwargs):
         namedValues = kwargs.pop('namedValues', self.namedValues)
-        clone = OctetString.clone(self, *args, **kwargs)
+        args = args and self.prettyIn(args[0], namedValues=namedValues)
+        clone = OctetString.clone(self, args, **kwargs)
         clone.namedValues = namedValues
         return clone
 
     def subtype(self, *args, **kwargs):
         namedValues = kwargs.pop('namedValues', self.namedValues)
-        clone = OctetString.subtype(self, *args, **kwargs)
+        args = args and self.prettyIn(args[0], namedValues=namedValues)
+        clone = OctetString.subtype(self, args, **kwargs)
         clone.namedValues = namedValues
         return clone
 
-    def prettyIn(self, bits):
+    def prettyIn(self, bits, namedValues=None):
         if not isinstance(bits, (tuple, list)):
             return OctetString.prettyIn(self, bits)  # raw bitstring
-        _octets = []
+        octets = []
         for bit in bits:  # tuple of named bits
-            v = self.namedValues.getValue(bit)
+            v = (namedValues or self.namedValues).getValue(bit)
             if v is None:
                 raise error.ProtocolError(
                     'Unknown named bit %s' % bit
                 )
             d, m = divmod(v, 8)
-            if d >= len(_octets):
-                _octets.extend([0] * (d - len(_octets) + 1))
-            _octets[d] |= 0x01 << (7 - m)
-        return OctetString.prettyIn(self, _octets)
+            if d >= len(octets):
+                octets.extend([0] * (d - len(octets) + 1))
+            octets[d] |= 0x01 << (7 - m)
+        return OctetString.prettyIn(self, octets)
 
     def prettyOut(self, value):
         names = []