Fix issue with cim_opeations.py pull ops and MaxObjectCount

Fix issue with MaxoObjectCount on PullInstances and PullInstancePaths
CIM_Operations.py methods.  The MaxObjectCount was defined as a keyword
parameter where it should have been be positional.  This should NOT
impact clients unless they did not supply the parameter at all so that
the result was None which is illegal(Pull... operations MUST include
MaxObjectCount).

Also extends these requests to test the Pull.. methods for valid
MaxObjectCount and context parameters. See issue #656

Adds mock tests for the new limits in the pull... requests and adds
pullinstance.yaml to mock tests.

Finally, changes run_cim_operations.py to use the prefered form for the
MaxObjectCount.

This pr adds a new test file for pullinstances mock tests.

docs/changes.rst

@@ -29,6 +29,14 @@ Enhancements
 Bug fixes
 ^^^^^^^^^
 
+* Fix issue with MaxoObjectCount on PullInstances and PullInstancePaths
+  CIM_Operations.py methods.  The MaxObjectCount was defined as a keyword
+  parameter where it should have been be positional.  This should NOT impact
+  clients unless they did not supply the parameter at all so that the result
+  was None which is illegal(Pull... operations MUST include MaxObjectCount).
+  Also extends these requests to test the Pull.. methods for valid
+  MaxObjectCount and context parameters. See issue #656.
+
 Build, test, quality
 ^^^^^^^^^^^^^^^^^^^^
 

pywbem/cim_operations.py

@@ -427,6 +427,24 @@ def _validateIterCommonParams(MaxObjectCount, OperationTimeout):
                          OperationTimeout)
 
 
+def _validatePullParams(MaxObjectCount, context):
+    """
+        Validate the input paramaters for the PullInstances,
+        PullInstancesWithPath, and PullInstancePaths.
+
+        MaxObjectCount: Must be integer type and ge 0
+
+        context: Must be not None and length ge 2
+    """
+    if (not isinstance(MaxObjectCount, six.integer_types) or
+            MaxObjectCount < 0):
+        raise ValueError('MaxObjectCount parameter must be integer >= 0 but '
+                         ' is %s' % MaxObjectCount)
+    if context is None or len(context) < 2:
+        raise ValueError('Pull... Context parameter must be valid tuple %s'
+                         % context)
+
+
 class WBEMConnection(object):  # pylint: disable=too-many-instance-attributes
     """
     A client's connection to a WBEM server. This is the main class of the
@@ -5268,6 +5286,7 @@ def PullInstancesWithPath(self, context, MaxObjectCount,
             * If zero, the WBEM server is to return no instances. This may
               be used by a client to leave the handling of any returned
               instances to a loop of Pull operations.
+            * None is not allowed for this attribute.
 
         Keyword Arguments:
 
@@ -5337,6 +5356,7 @@ def PullInstancesWithPath(self, context, MaxObjectCount,
                 **extra)
 
         try:
+            _validatePullParams(MaxObjectCount, context)
 
             namespace = context[1]
 
@@ -5362,7 +5382,7 @@ def PullInstancesWithPath(self, context, MaxObjectCount,
                 self.operation_recorder.record_staged()
             return result_tuple
 
-    def PullInstancePaths(self, context, MaxObjectCount=None, **extra):
+    def PullInstancePaths(self, context, MaxObjectCount, **extra):
         # pylint: disable=invalid-name
 
         """
@@ -5403,6 +5423,7 @@ def PullInstancePaths(self, context, MaxObjectCount=None, **extra):
             * If zero, the WBEM server is to return no instances. This may
               be used by a client to leave the handling of any returned
               instances to a loop of Pull operations.
+            * None is not allowed for this attribute.
 
         Keyword Arguments:
 
@@ -5469,9 +5490,14 @@ def PullInstancePaths(self, context, MaxObjectCount=None, **extra):
                 **extra)
 
         try:
+            _validatePullParams(MaxObjectCount, context)
 
             namespace = context[1]
 
+            if MaxObjectCount is None or MaxObjectCount < 0:
+                raise ValueError('MaxObjectCount must be >= 0 but is %s' %
+                                 MaxObjectCount)
+
             result = self._imethodcall(
                 'PullInstancePaths',
                 namespace=namespace,
@@ -5494,7 +5520,7 @@ def PullInstancePaths(self, context, MaxObjectCount=None, **extra):
                 self.operation_recorder.record_staged()
             return result_tuple
 
-    def PullInstances(self, context, MaxObjectCount=None, **extra):
+    def PullInstances(self, context, MaxObjectCount, **extra):
         # pylint: disable=invalid-name
         """
         Retrieve the next set of instances from an open enumeraton
@@ -5534,6 +5560,7 @@ def PullInstances(self, context, MaxObjectCount=None, **extra):
             * If zero, the WBEM server is to return no instances. This may
               be used by a client to leave the handling of any returned
               instances to a loop of Pull operations.
+            * None is not allowed for this attribute.
 
         Keyword Arguments:
 
@@ -5597,6 +5624,7 @@ def PullInstances(self, context, MaxObjectCount=None, **extra):
                 **extra)
 
         try:
+            _validatePullParams(MaxObjectCount, context)
 
             namespace = context[1]