models: Add fields for series sequences

* Add ManyToMany field to represent a new series that will supersed
  another, or is superseded by another.
* Add show_series_versions to enable this feature in a project

Signed-off-by: Victor Accarini <[email protected]>

Author: victor-accarini

patchwork/migrations/0049_series_sequences.py

@@ -0,0 +1,31 @@
+# Generated by Django 5.1.4 on 2025-03-20 01:28
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+    dependencies = [
+        ('patchwork', '0048_series_dependencies'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='series',
+            name='supersedes',
+            field=models.ManyToManyField(
+                blank=True,
+                help_text='Previous versions of this patch.',
+                related_name='superseded',
+                to='patchwork.series',
+            ),
+        ),
+        migrations.AddField(
+            model_name='project',
+            name='show_series_versions',
+            field=models.BooleanField(
+                default=False,
+                help_text='Enable parsing series previous versions on patches '
+                'and cover letters.',
+            ),
+        ),
+    ]

patchwork/models.py

@@ -104,6 +104,11 @@ class Project(models.Model):
         default=False,
         help_text='Enable dependency tracking for patches and cover letters.',
     )
+    show_series_versions = models.BooleanField(
+        default=False,
+        help_text='Enable parsing series previous versions on patches and '
+        'cover letters.',
+    )
     use_tags = models.BooleanField(default=True)
 
     def is_editable(self, user):
@@ -858,6 +863,15 @@ class Series(FilenameMixin, models.Model):
         related_query_name='dependent',
     )
 
+    # versioning
+    supersedes = models.ManyToManyField(
+        'self',
+        symmetrical=False,
+        blank=True,
+        help_text='Previous versions of this patch.',
+        related_name='superseded',
+    )
+
     # metadata
     name = models.CharField(
         max_length=255,
@@ -889,6 +903,15 @@ def _format_name(obj):
             return match.group(2)
         return obj.name.strip()
 
+    def is_editable(self, user):
+        if not user.is_authenticated:
+            return False
+
+        if user.is_superuser or user == self.submitter.user:
+            return True
+
+        return self.project.is_editable(user)
+
     @property
     def received_total(self):
         return self.patches.count()