Fix #1017 - Exception caused by activity being set on incorrect foreign key

The .activity ForeignKey on several models such as MediaEntry expects
	a ActivityIntmediatory ID not an Activity ID however in submit code the
	activity attribute was being set the Activity, simply removing this
	assignment should fix the issue as everything is set correctly at this point.

	I have also moved the creation of the activity above the processing of media
	to avoid race conditions.

mediagoblin/submit/lib.py

@@ -195,18 +195,18 @@ def submit_media(mg_app, user, submitted_file, filename,
     else:
         feed_url = None
 
+    add_comment_subscription(user, entry)
+
+    # Create activity
+    create_activity("post", entry, entry.uploader)
+    entry.save()
+
     # Pass off to processing
     #
     # (... don't change entry after this point to avoid race
     # conditions with changes to the document via processing code)
     run_process_media(entry, feed_url)
 
-    add_comment_subscription(user, entry)
-
-    # Create activity
-    entry.activity = create_activity("post", entry, entry.uploader).id
-    entry.save()
-
     return entry
 
 
@@ -291,11 +291,11 @@ def api_add_to_feed(request, entry):
         qualified=True, user=request.user.username
     )
 
-    run_process_media(entry, feed_url)
     add_comment_subscription(request.user, entry)
 
     # Create activity
-    entry.activity = create_activity("post", entry, entry.uploader).id
+    create_activity("post", entry, entry.uploader)
     entry.save()
+    run_process_media(entry, feed_url)
 
     return json_response(entry.serialize(request))

mediagoblin/user_pages/views.py

@@ -195,15 +195,14 @@ def media_post_comment(request, media):
             messages.ERROR,
             _("Oops, your comment was empty."))
     else:
+        create_activity("post", comment, comment.author, target=media)
+        add_comment_subscription(request.user, media)
         comment.save()
 
         messages.add_message(
             request, messages.SUCCESS,
             _('Your comment has been posted!'))
-
         trigger_notification(comment, media, request)
-        create_activity("post", comment, comment.author, target=media)
-        add_comment_subscription(request.user, media)
 
     return redirect_obj(request, media)
 
@@ -263,8 +262,8 @@ def media_collect(request, media):
         collection.description = form.collection_description.data
         collection.creator = request.user.id
         collection.generate_slug()
-        collection.save()
         create_activity("create", collection, collection.creator)
+        collection.save()
 
     # Otherwise, use the collection selected from the drop-down
     else: