Update start_post_id when starting a discussion

framework/core/src/Core/Handlers/Commands/StartDiscussionCommandHandler.php

@@ -44,9 +44,12 @@ class StartDiscussionCommandHandler
         // attributes as posting the reply will have changed some of them (e.g.
         // last_time.)
         $discussion->setRawAttributes($post->discussion->getAttributes(), true);
+        $discussion->setStartPost($post);
 
         $this->dispatchEventsFor($discussion);
 
+        $discussion->save();
+
         return $post->discussion;
     }
 }

framework/core/src/Core/Models/Discussion.php

@@ -134,6 +134,21 @@ class Discussion extends Model
         return $this;
     }
 
+    /**
+     * Set the discussion's start post details.
+     *
+     * @param  \Flarum\Core\Models\Post  $post
+     * @return $this
+     */
+    public function setStartPost(Post $post)
+    {
+        $this->start_time    = $post->time;
+        $this->start_user_id = $post->user_id;
+        $this->start_post_id = $post->id;
+
+        return $this;
+    }
+
     /**
      * Set the discussion's last post details.
      *
@@ -350,6 +365,10 @@ class Discussion extends Model
      */
     public function stateFor(User $user)
     {
+        // If the state is already eager-loaded, we'll return that.
+        // Unfortunately we can't check to see if the user ID is the same,
+        // because the user may not have a state entry, in which case the loaded
+        // relation will be null.
         if ($this->isRelationLoaded('state')) {
             return $this->relations['state'];
         }