Change submission pending_status to work like grants

Fix #4460: Instead of trying to keep pending_status in sync with status,
now assume that if pending_status is None, there isn''t any pending change.
While if it is set, it means the submission new pending status is the
one set in the variable.

Changes:
- Update pending_status field to allow null=True
- Remove automatic sync logic from save method
- Add current_or_pending_status property
- Update admin queryset to filter by null pending_status
- Update reviews template to use current_or_pending_status
- Update tests to reflect new behavior

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-authored-by: Marco Acierno <marcoacierno@users.noreply.github.com>

Author: claude[bot]

backend/reviews/templates/proposals-recap.html

@@ -394,14 +394,14 @@ <h3>Show proposals with pending status:</h3>
               <script>
                 submissionsById[{{ item.id }}] = {
                   id: {{ item.id }},
-                  status: "{{ item.pending_status }}",
-                  originalStatus: "{{ item.pending_status }}",
+                  status: "{{ item.current_or_pending_status }}",
+                  originalStatus: "{{ item.current_or_pending_status }}",
                   audienceLevel: {{ item.audience_level.id }},
                   languages: [{% for language in item.languages.all %}"{{language.code}}",{% endfor %}],
                   numOfVotes: {{item.userreview_set.count}},
                 };
               </script>
-              <tr class="proposal-item" id="submission-{{item.id}}" data-original-status="{{ item.pending_status }}">
+              <tr class="proposal-item" id="submission-{{item.id}}" data-original-status="{{ item.current_or_pending_status }}">
                 <td>{{forloop.counter}}</td>
                 <td class="results-title">
                   <a

backend/submissions/admin.py

@@ -425,7 +425,7 @@ def get_queryset(self, request):
             super()
             .get_queryset(request)
             .exclude(
-                pending_status=F("status"),
+                pending_status__isnull=True,
             )
         )
 

backend/submissions/migrations/0028_alter_submission_pending_status_to_null.py

@@ -0,0 +1,18 @@
+# Generated by Django 5.1.4 on 2025-08-03 17:52
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('submissions', '0027_submissionconfirmpendingstatusproxy'),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name='submission',
+            name='pending_status',
+            field=models.CharField(blank=True, choices=[('proposed', 'Proposed'), ('accepted', 'Accepted'), ('waiting_list', 'Waiting list'), ('rejected', 'Rejected'), ('cancelled', 'Cancelled')], max_length=20, null=True, verbose_name='pending status'),
+        ),
+    ]

backend/submissions/models.py

@@ -104,14 +104,15 @@ class Submission(TimeStampedModel):
         _("status"), choices=STATUS, max_length=20, default=STATUS.proposed
     )
     pending_status = models.CharField(
-        _("pending status"), choices=STATUS, max_length=20, default="", blank=True
+        _("pending status"), choices=STATUS, max_length=20, null=True, blank=True
     )
 
     objects = SubmissionQuerySet().as_manager()
 
     def __init__(self, *args, **kwargs):
         super().__init__(*args, **kwargs)
         self._original_status = self.status
+        self._original_pending_status = self.pending_status
 
     @property
     def hashid(self):
@@ -197,13 +198,14 @@ def save(self, *args, **kwargs):
             if update_fields:
                 update_fields.append("slug")
 
-        if self.pending_status == self._original_status:
-            self.pending_status = self.status
-
-            if update_fields:
-                update_fields.append("pending_status")
+        super().save(*args, **kwargs)
+        
+        self._original_pending_status = self.pending_status
+        self._original_status = self.status
 
-        return super().save(*args, **kwargs)
+    @property
+    def current_or_pending_status(self):
+        return self.pending_status or self.status
 
     def __str__(self):
         return (

backend/submissions/tests/test_models.py

@@ -26,31 +26,34 @@ def test_slug_is_not_regenerated_when_changing_title():
     assert submission.slug == "ciao"
 
 
-def test_syncs_pending_status_when_changing_status():
+def test_current_or_pending_status_returns_pending_if_set():
     submission = SubmissionFactory(
-        status=Submission.STATUS.accepted,
+        status=Submission.STATUS.proposed,
         pending_status=Submission.STATUS.accepted,
     )
 
-    submission.status = Submission.STATUS.rejected
-    submission.save(update_fields=["status"])
+    assert submission.current_or_pending_status == Submission.STATUS.accepted
 
-    submission.refresh_from_db()
 
-    assert submission.status == Submission.STATUS.rejected
-    assert submission.pending_status == Submission.STATUS.rejected
+def test_current_or_pending_status_returns_current_if_pending_none():
+    submission = SubmissionFactory(
+        status=Submission.STATUS.rejected,
+        pending_status=None,
+    )
 
+    assert submission.current_or_pending_status == Submission.STATUS.rejected
 
-def test_leaves_pending_status_unchanged_if_different():
+
+def test_pending_status_not_automatically_synced():
     submission = SubmissionFactory(
         status=Submission.STATUS.proposed,
-        pending_status=Submission.STATUS.rejected,
+        pending_status=Submission.STATUS.accepted,
     )
 
-    submission.status = Submission.STATUS.waiting_list
-    submission.save()
+    submission.status = Submission.STATUS.rejected
+    submission.save(update_fields=["status"])
 
     submission.refresh_from_db()
 
-    assert submission.status == Submission.STATUS.waiting_list
-    assert submission.pending_status == Submission.STATUS.rejected
+    assert submission.status == Submission.STATUS.rejected
+    assert submission.pending_status == Submission.STATUS.accepted  # Should remain unchanged