Issue #2786, compiler does not test arrayness of instance property va…

…lues

The MOF compiler completely ignores issues of mismatch between the class
definition of properties arrayness and the corresponding values in
instances of the class. Thus, the compiler where a class with an array
property is defined will accept a single value property value (and
output it as a single value property value) and will accept an array
value defintion for an instance and produce an array value in the
CIMProperty.  This fix tests for this mismatch in the compiler and
generates an error if found.

docs/changes.rst

@@ -126,6 +126,10 @@ Released: not yet
     use mock versions of _imethodcall and _methodcall and simply duck typed
     the methods. (see issue #2755)
 
+* Fixes MOF compiler issue  where the compiler was allowing array properties
+  to have corresponding instances instantiated with non-array values and
+  vice-versa. This now causes a parse error. (See issue # 2786)
+
 * Docs: Fixed an error with the autodocsumm and Sphinx 4.0.0. (issue #2697)
 
 * Jupyter Notebook: Ignored safety issues 40380..40386 in order to continue

pywbem/_mof_compiler.py

@@ -1876,7 +1876,7 @@ def p_instanceDeclaration(p):
                                                    in allowed_types])
                             raise MOFParseError(
                                 msg=_format(
-                                    "Property {0|A} with value {1|A} embedded "
+                                    "Property {0!A} with value {1!A} embedded "
                                     "object type must be ((1}). Actual type "
                                     "is {2}", cprop.name, cls_names, type(obj)))
                     # If the compile produces no objects there must have
@@ -1885,14 +1885,27 @@ def p_instanceDeclaration(p):
                     if not objs:
                         raise MOFParseError(
                             msg=_format(
-                                "Property {0|A} with value {1|A} embedded"
+                                "Property {0!A} with value {1!A} embedded"
                                 " object compile produced no instances.",
                                 cprop.name, pval))
 
                     # If array type insert list, else insert item 0 from list
                     pprop.value = objs if cprop.is_array else objs[0]
                     pprop.embedded_object = embedded_object_type
             else:
+                if pval:
+                    ival_is_array = isinstance(pval, list)
+                    if cprop.is_array != ival_is_array:
+                        raise MOFParseError(
+                            msg=_format(
+                                "Property {0!A} value {1!A} in instance of "
+                                "class {2!A} has class and instance array "
+                                "mismatch. The class definition is "
+                                "array={3} instance value type is array={4} "
+                                "for value type {5}",
+                                pname, pval, cc.classname, cprop.is_array,
+                                ival_is_array, type(pval)),
+                            parser_token=p)
                 pprop.value = cimvalue(pval, cprop.type)
             inst.properties[pname] = pprop
         except ValueError as ve: