Fix some activity errors

apps/activity/forms.py

@@ -1,9 +1,11 @@
 # Copyright (C) 2018-2020 by BDE ENS Paris-Saclay
 # SPDX-License-Identifier: GPL-3.0-or-later
-from datetime import timedelta, datetime
+
+from datetime import timedelta
 
 from django import forms
 from django.contrib.contenttypes.models import ContentType
+from django.utils import timezone
 from django.utils.translation import gettext_lazy as _
 from member.models import Club
 from note.models import NoteUser, Note
@@ -41,7 +43,7 @@ class GuestForm(forms.ModelForm):
     def clean(self):
         cleaned_data = super().clean()
 
-        if self.activity.date_start > datetime.now():
+        if self.activity.date_start > timezone.now():
             self.add_error("inviter", _("You can't invite someone once the activity is started."))
 
         if not self.activity.valid:

apps/activity/models.py

@@ -1,7 +1,7 @@
 # Copyright (C) 2018-2020 by BDE ENS Paris-Saclay
 # SPDX-License-Identifier: GPL-3.0-or-later
 
-from datetime import timedelta, datetime
+from datetime import timedelta
 from threading import Thread
 
 from django.conf import settings
@@ -236,7 +236,7 @@ class Guest(models.Model):
         one_year = timedelta(days=365)
 
         if not force_insert:
-            if self.activity.date_start > datetime.now():
+            if self.activity.date_start > timezone.now():
                 raise ValidationError(_("You can't invite someone once the activity is started."))
 
             if not self.activity.valid:

apps/activity/views.py

@@ -125,7 +125,7 @@ class ActivityEntryView(LoginRequiredMixin, TemplateView):
             .filter(PermissionBackend.filter_queryset(self.request.user, Guest, "view"))\
             .order_by('last_name', 'first_name').distinct()
 
-        if "search" in self.request.GET:
+        if "search" in self.request.GET and self.request.GET["search"]:
             pattern = self.request.GET["search"]
             if pattern[0] != "^":
                 pattern = "^" + pattern