Better checking of "None" in string fields

Author: ibmmqmet

code/ibmmq/mqcallback.py

@@ -121,7 +121,9 @@ def _internal_cb(hc, md, gmo, buf, cbc):
     else:
         gmo_up = GMO()
 
-    # Call the real user function with the unpacked forms of the structures
+    # Call the real user function with the unpacked forms of the structures.
+    # If the callback_function is actually a method within a class, then the "self"
+    # parameter is automatically added to the parameters.
     cb.callback_function(queue_manager=qmgr, queue=queue, md=md_up, gmo=gmo_up, msg=buf, cbc=cbc_up)
 
 def real_cb(obj, kwargs):

code/ibmmq/mqopts.py

@@ -130,19 +130,32 @@ def pack(self) -> bytes:
         # are in the list elements.
         for i in self.__list:
             v = getattr(self, i[0])
+
             # Flatten attribs that are arrays
             if isinstance(v, list):
                 for x in v:
                     args.append(ensure_strings_are_bytes(x))
             else:
-                # print(f"{i[0]} is of value {v}: type {type(v)}")
+                # print(f"Field: {i[0]} format '{i[2]}' is of value {v}: type {type(v)}")
                 if i[0] in _binary_fields:
                     if not isinstance(v, bytes):
                         err = f'{i[0]} must be a byte array'
                         raise TypeError(err)
+                elif v is None:
+                    # If a string field is set to None, the pack() function
+                    # fails with an unobvious error. Let's try to diagnose
+                    # it a bit earlier. And if there's a Pointer that has escaped being
+                    # set to NULL, then fix it up.
+                    if i[2].endswith('s'):
+                        err = f'Class:{type(self).__name__} Field:{i[0]} must not be None'
+                        raise TypeError(err)
+                    if i[2] == 'P':
+                        v = 0
+
                 args.append(ensure_strings_are_bytes(v))
 
         # print(f"Args to be packed are {args}")
+
         return struct.pack(*args)
 
     def unpack(self, buff: bytes):

code/ibmmq/mqqmgr.py

@@ -231,10 +231,8 @@ def connect_with_options(self, name: Union[str, bytes], *args: Any, **kwargs: Di
             csp._set_ptr_field('Token', token)
 
             # We need to fix these up even if they are not going to be used
-            if user:
-                csp._set_ptr_field('CSPUserId', None)
-            if password:
-                csp._set_ptr_field('CSPPassword', None)
+            csp._set_ptr_field('CSPUserId', None)
+            csp._set_ptr_field('CSPPassword', None)
 
             csp.AuthenticationType = CMQC.MQCSP_AUTH_ID_TOKEN
             csp.Version = max(csp.Version, CMQC.MQCSP_VERSION_3)
@@ -249,6 +247,10 @@ def connect_with_options(self, name: Union[str, bytes], *args: Any, **kwargs: Di
             csp._set_ptr_field('CSPUserId', user)
             csp._set_ptr_field('CSPPassword', password)
             csp.AuthenticationType = CMQC.MQCSP_AUTH_USER_ID_AND_PWD
+        else:
+            # Force these to be None
+            csp._set_ptr_field('CSPUserId', None)
+            csp._set_ptr_field('CSPPassword', None)
 
         if initial_key:
             csp._set_ptr_field('InitialKey', initial_key)