5 files changed, 88 insertions, 4 deletions

diff --git a/src/mailman/app/subscriptions.py b/src/mailman/app/subscriptions.py
index ca84e091f..04e0955cb 100644
--- a/src/mailman/app/subscriptions.py
+++ b/src/mailman/app/subscriptions.py
@@ -44,6 +44,7 @@ from mailman.interfaces.subscriptions import (
     ISubscriptionService, MissingUserError, RequestRecord)
 from mailman.interfaces.user import IUser
 from mailman.interfaces.usermanager import IUserManager
+from mailman.interfaces.workflowstate import IWorkflowStateManager
 from mailman.model.member import Member
 from mailman.utilities.datetime import now
 
@@ -74,6 +75,7 @@ class SubscriptionWorkflow:
         self.pre_verified = pre_verified
         self.pre_confirmed = pre_confirmed
         self.pre_approved = pre_approved
+        self._save_key = "{}:{}".format(self.mlist.list_id, self.address.email)
         # Prepare the state machine.
         self._next = deque()
         self._next.append("verification_check")
@@ -95,6 +97,20 @@ class SubscriptionWorkflow:
         except:
             raise
 
+    def save_state(self):
+        manager = getUtility(IWorkflowStateManager)
+        # Note: only the next step is saved, not the whole stack. Not an issue
+        # since there's never more than a single step in the queue anyway.
+        # Also: we don't save & restore the self.pre_* variables, but we could,
+        # using the data argument.
+        manager.save(self.__class__.__name__, self._save_key, self._next[0])
+
+    def restore_state(self):
+        manager = getUtility(IWorkflowStateManager)
+        state = manager.restore(self.__class__.__name__, self._save_key)
+        if state is not None:
+            self._next[0] = state.step
+
     def _maybe_set_preferred_address(self):
         if self.user is None:
             # The address has no linked user so create one, link it, and set
diff --git a/src/mailman/app/tests/test_subscriptions.py b/src/mailman/app/tests/test_subscriptions.py
index 7bb59bb45..97dbd8382 100644
--- a/src/mailman/app/tests/test_subscriptions.py
+++ b/src/mailman/app/tests/test_subscriptions.py
@@ -82,6 +82,21 @@ class TestSubscriptionWorkflow(unittest.TestCase):
         self._anne = 'anne@example.com'
         self._user_manager = getUtility(IUserManager)
 
+    def test_save_restore(self):
+        anne = self._user_manager.create_address(self._anne, 'Anne Person')
+        workflow = SubscriptionWorkflow(
+            self._mlist, anne,
+            pre_verified=True, pre_confirmed=False, pre_approved=False)
+        next(workflow)
+        next_step = workflow._next[0]
+        workflow.save_state()
+        # Now create a new instance and restore
+        workflow = SubscriptionWorkflow(
+            self._mlist, anne,
+            pre_verified=True, pre_confirmed=False, pre_approved=False)
+        workflow.restore_state()
+        self.assertEqual(next_step, workflow._next[0])
+
     def test_preverified_address_joins_open_list(self):
         # The mailing list has an open subscription policy, so the subscriber
         # becomes a member with no human intervention.
diff --git a/src/mailman/config/configure.zcml b/src/mailman/config/configure.zcml
index 6f5876aa8..f6cb6dac1 100644
--- a/src/mailman/config/configure.zcml
+++ b/src/mailman/config/configure.zcml
@@ -118,8 +118,8 @@
    />
 
   <utility
-    provides="mailman.interfaces.workflowstate.IWorkflowState"
-    factory="mailman.model.workflowstate.WorkflowState"
+    provides="mailman.interfaces.workflowstate.IWorkflowStateManager"
+    factory="mailman.model.workflowstate.WorkflowStateManager"
     />
 
 </configure>
diff --git a/src/mailman/interfaces/workflowstate.py b/src/mailman/interfaces/workflowstate.py
index bb08fef2d..186386170 100644
--- a/src/mailman/interfaces/workflowstate.py
+++ b/src/mailman/interfaces/workflowstate.py
@@ -19,6 +19,7 @@
 
 __all__ = [
     'IWorkflowState',
+    'IWorkflowStateManager',
     ]
 
 
@@ -27,7 +28,7 @@ from zope.interface import Interface, Attribute
 
 
 class IWorkflowState(Interface):
-    """A basic user."""
+    """The state of a workflow."""
 
     name = Attribute(
         """The name of the workflow.""")
@@ -40,3 +41,30 @@ class IWorkflowState(Interface):
 
     data = Attribute(
         """Additional data (may be JSON-encodedeJSON .""")
+
+
+
+class IWorkflowStateManager(Interface):
+    """The workflow states manager."""
+
+    def save(name, key, step, data=None):
+        """Save the state of a workflow
+
+        :param name: The name of the workflow.
+        :type name: str
+        :param key: A unique key identifying this workflow instance.
+        :type key: str
+        :param step: The next step for this workflow.
+        :type step: str
+        :param data: Additional data (workflow-specific).
+        :type data: str
+        """
+
+    def restore(name, key):
+        """Get the saved state for a workflow or None if nothing was saved.
+
+        :param name: The name of the workflow.
+        :type name: str
+        :param key: A unique key identifying this workflow instance.
+        :type key: str
+        """
diff --git a/src/mailman/model/workflowstate.py b/src/mailman/model/workflowstate.py
index 5e3301dcf..ee0226d61 100644
--- a/src/mailman/model/workflowstate.py
+++ b/src/mailman/model/workflowstate.py
@@ -19,11 +19,14 @@
 
 __all__ = [
     'WorkflowState',
+    'WorkflowStateManager',
     ]
 
 
 from mailman.database.model import Model
-from mailman.interfaces.workflowstate import IWorkflowState
+from mailman.database.transaction import dbconnection
+from mailman.interfaces.workflowstate import (
+    IWorkflowState, IWorkflowStateManager)
 from sqlalchemy import Column, Unicode
 from zope.interface import implementer
 
@@ -39,3 +42,25 @@ class WorkflowState(Model):
     key = Column(Unicode, primary_key=True)
     step = Column(Unicode, nullable=False)
     data = Column(Unicode)
+
+
+
+@implementer(IWorkflowStateManager)
+class WorkflowStateManager:
+    """See `IWorkflowStateManager`."""
+
+    @dbconnection
+    def save(self, store, name, key, step, data=None):
+        """See `IWorkflowStateManager`."""
+        state = store.query(WorkflowState).get((name, key))
+        if state is None:
+            state = store.add(WorkflowState(
+                name=name, key=key, step=step, data=data))
+        else:
+            state.step = step
+            state.data = data
+
+    @dbconnection
+    def restore(self, store, name, key):
+        """See `IWorkflowStateManager`."""
+        return store.query(WorkflowState).get((name, key))