Merge branch 'fix/start-reminder-users' into 'master'

Fix start reminder users slicing

Closes #989

See merge request !1440

Dockerfile

@@ -34,7 +34,7 @@ RUN apt-get update && apt-get install -y --no-install-recommends \
     rm -rf /var/lib/apt
 
 RUN pip install --no-cache-dir poetry && \
-    poetry config settings.virtualenvs.create false
+    poetry config virtualenvs.create false
 
 WORKDIR /usr/src/app/website/
 # install python requirements
@@ -46,7 +46,7 @@ RUN if [ "$install_dev_requirements" -eq 1 ]; then \
         echo "This will fail if the dependencies are out of date"; \
         poetry install --no-interaction --no-dev; \
     fi; \
-    poetry cache:clear --all --no-interaction pypi
+    poetry cache clear --all --no-interaction pypi
 
 # Create entry points
 COPY resources/entrypoint.sh /usr/local/bin/entrypoint.sh

website/events/models.py

@@ -395,8 +395,8 @@ class Event(models.Model, metaclass=ModelTranslateMeta):
                 self.start_reminder = start_reminder
                 if self.registration_required:
                     self.start_reminder.users.set(
-                            self.participants.filter(member__isnull=False)
-                                .values_list('member', flat=True))
+                        [r.member for r in self.participants
+                         if r.member])
                 else:
                     self.start_reminder.users.set(Member.current_members.all())
             elif start_reminder.pk is not None: