Do not set namespace dict where exec is executed into as a default parameter dict.

When load() was called in checkConsistency where namespace_dict was not given
and thus equal to the default function parameter value, exec would set the
function namespace_dict parameter, thus the next call would have
namespace_dict already set when it was given.

This fixes testInvalidSourceCode when being ran for TestZodbExtensionComponent
and TestZodbDocumentComponent in the same runUnitTest.

product/ERP5Type/mixin/component.py

@@ -201,7 +201,7 @@ class ComponentMixin(PropertyRecordableMixin, Base):
     else:
       message = None
       try:
-        self.load(text_content=text_content)
+        self.load({}, text_content=text_content)
       except SyntaxError, e:
         mapping = dict(error_message=str(e),
                        line_number=e.lineno,
@@ -266,14 +266,18 @@ class ComponentMixin(PropertyRecordableMixin, Base):
             for error in current_workflow.get('error_message', [])]
 
   security.declareProtected(Permissions.ModifyPortalContent, 'load')
-  def load(self, namespace_dict={}, validated_only=False, text_content=None):
+  def load(self, namespace_dict, validated_only=False, text_content=None):
     """
     Load the source code into the given dict. Using exec() rather than
     imp.load_source() as the latter would required creating an intermediary
     file. Also, for traceback readability sake, the destination module
-    __dict__ is given rather than creating an empty dict and returning
-    it. By default namespace_dict is an empty dict to allow checking the
-    source code before validate.
+    __dict__ is given rather than creating an empty dict and returning it.
+
+    Initially, namespace_dict default parameter value was an empty dict to
+    allow checking the source code before validate, but this introduces a bug
+    when namespace_dict was not given because the first call would exec
+    directly into function namespace_dict default parameter, thus the second
+    call would have namespace_dict default value to the previous call.
     """
     if text_content is None:
       text_content = self.getTextContent(validated_only=validated_only)

product/ERP5Type/tests/testDynamicClassGeneration.py

@@ -1474,12 +1474,14 @@ class _TestZodbComponent(SecurityTestCase):
     self.assertEquals(component.getTextContent(validated_only=True), valid_code)
     self.assertModuleImportable('TestComponentWithSyntaxError')
 
-    invalid_code_dict = {
-      None: ComponentMixin._message_text_content_not_set,
-      'def foobar(*args, **kwargs)\n  return 42': 'Syntax error in source code:',
-      'foobar': 'Source code:'}
-
-    for invalid_code, error_message in invalid_code_dict.iteritems():
+    # Make sure that foobar NameError is at the end to make sure that after
+    # defining foobar function, the symbol is not available anymore
+    invalid_code_dict = (
+      (None, ComponentMixin._message_text_content_not_set),
+      ('def foobar(*args, **kwargs)\n  return 42', 'Syntax error in source code:'),
+      ('foobar', 'Source code:'))
+
+    for invalid_code, error_message in invalid_code_dict:
       ComponentTool.reset = assertResetNotCalled
       try:
         component.setTextContent(invalid_code)