Subscription::ensureStart skips AlreadyFulfilledException

Sometimes we just want to accept the user's wrong, but when it comes
to remote APIs etc. we probably want to let the client know it has
done something already (in this case multiple identical subscription
requests - which might indicate to it that it should refresh the sub
lists or something).

actions/apifriendshipscreate.php

@@ -100,8 +100,8 @@ class ApiFriendshipsCreateAction extends ApiAuthAction
 
         try {
             Subscription::start($this->scoped, $this->other);
-        } catch (Exception $e) {
-            $this->clientError($e->getMessage(), 403);
+        } catch (AlreadyFulfilledException $e) {
+            $this->clientError($e->getMessage(), 409);
         }
 
         $this->initDocument($this->format);

actions/atompubsubscriptionfeed.php

@@ -230,18 +230,11 @@ class AtompubsubscriptionfeedAction extends AtompubAction
                 $this->clientError(sprintf(_('Unknown profile %s.'), $person->id));
             }
 
-            if (Subscription::exists($this->_profile, $profile)) {
+            try {
+                $sub = Subscription::start($this->_profile, $profile);
+            } catch (AlreadyFulfilledException $e) {
                 // 409 Conflict
-                // TRANS: Client error displayed trying to subscribe to an already subscribed profile.
-                // TRANS: %s is the profile the user already has a subscription on.
-                $this->clientError(sprintf(_('Already subscribed to %s.'),
-                                           $person->id),
-                                   409);
-            }
-
-            if (Subscription::start($this->_profile, $profile)) {
-                $sub = Subscription::pkeyGet(array('subscriber' => $this->_profile->id,
-                                                   'subscribed' => $profile->id));
+                $this->clientError($e->getMessage(), 409);
             }
 
             Event::handle('EndAtomPubNewActivity', array($activity, $sub));

actions/invite.php

@@ -118,7 +118,7 @@ class InviteAction extends Action
                         $this->already[] = $other;
                     } else {
                         try {
-                            Subscription::start($profile, $other);
+                            Subscription::ensureStart($profile, $other);
                             $this->subbed[] = $other;
                         } catch (Exception $e) {
                             // subscription failed, but keep working

actions/subscribe.php

@@ -122,7 +122,7 @@ class SubscribeAction extends Action
     {
         // Throws exception on error
 
-        $sub = Subscription::start($this->user->getProfile(),
+        $sub = Subscription::ensureStart($this->user->getProfile(),
                                    $this->other);
 
         if ($this->boolean('ajax')) {

classes/Subscription.php

@@ -94,6 +94,7 @@ class Subscription extends Managed_DataObject
         if (Event::handle('StartSubscribe', array($subscriber, $other))) {
             $otherUser = User::getKV('id', $other->id);
             if ($otherUser instanceof User && $otherUser->subscribe_policy == User::SUBSCRIBE_POLICY_MODERATE && !$force) {
+                // Will throw an AlreadyFulfilledException if this queue item already exists.
                 $sub = Subscription_queue::saveNew($subscriber, $other);
                 $sub->notify();
             } else {
@@ -132,6 +133,17 @@ class Subscription extends Managed_DataObject
         return $sub;
     }
 
+    static function ensureStart(Profile $subscriber, Profile $other, $force=false)
+    {
+        try {
+            $sub = self::start($subscriber, $other, $force);
+        } catch (AlreadyFulfilledException $e) {
+            // Nothing to see here, move along...
+            return self::getSubscription($subscriber, $other);
+        }
+        return $sub;
+    }
+
     /**
      * Low-level subscription save.
      * Outside callers should use Subscription::start()

classes/Subscription_queue.php

@@ -36,6 +36,9 @@ class Subscription_queue extends Managed_DataObject
 
     public static function saveNew(Profile $subscriber, Profile $subscribed)
     {
+        if (self::exists($subscriber, $subscribed)) {
+            throw new AlreadyFulfilledException(_('This subscription request is already in progress.'));
+        }
         $rq = new Subscription_queue();
         $rq->subscriber = $subscriber->id;
         $rq->subscribed = $subscribed->id;

classes/User.php

@@ -354,7 +354,7 @@ class User extends Managed_DataObject
                     common_log(LOG_WARNING, sprintf("Default user %s does not exist.", $defnick),
                                __FILE__);
                 } else {
-                    Subscription::start($profile, $defuser->getProfile());
+                    Subscription::ensureStart($profile, $defuser->getProfile());
                 }
             }
 

lib/activityimporter.php

@@ -109,7 +109,7 @@ class ActivityImporter extends QueueHandler
 
             // XXX: don't do this for untrusted input!
 
-            Subscription::start($otherProfile, $profile);
+            Subscription::ensureStart($otherProfile, $profile);
         } else if (empty($activity->actor)
                    || $activity->actor->id == $author->id) {
 
@@ -123,7 +123,7 @@ class ActivityImporter extends QueueHandler
                 throw new ClientException(_('Unknown profile.'));
             }
 
-            Subscription::start($profile, $otherProfile);
+            Subscription::ensureStart($profile, $otherProfile);
         } else {
             // TRANS: Client exception thrown when trying to import an event not related to the importing user.
             throw new Exception(_('This activity seems unrelated to our user.'));

lib/activitymover.php

@@ -146,7 +146,7 @@ class ActivityMover extends QueueHandler
                                "Changing sub to {$act->objects[0]->id}".
                                "by {$act->actor->id} to {$remote->nickname}.");
                     $otherProfile = $otherUser->getProfile();
-                    Subscription::start($otherProfile, $remote);
+                    Subscription::ensureStart($otherProfile, $remote);
                     Subscription::cancel($otherProfile, $user->getProfile());
                 } else {
                     $this->log(LOG_NOTICE,