[damned-lies] Prevent cascade deleting relate actions of deleted accounts

[Claude Paroz <claudep src gnome org>]

commit 0ba0c5d2ed45728bc433a78927be7db3235e3177
Author: Claude Paroz <claude 2xlibre net>
Date:   Mon Mar 22 22:29:22 2021 +0100

    Prevent cascade deleting relate actions of deleted accounts

 people/templatetags/people.py                      |  4 ++--
 templates/vertimus/vertimus_detail.html            |  6 +++++-
 .../migrations/0008_actions_on_delete_setnull.py   | 22 ++++++++++++++++++++++
 vertimus/models.py                                 |  4 ++--
 4 files changed, 31 insertions(+), 5 deletions(-)
---
diff --git a/people/templatetags/people.py b/people/templatetags/people.py
index 4770c69f..3acf4616 100644
--- a/people/templatetags/people.py
+++ b/people/templatetags/people.py
@@ -26,7 +26,7 @@ def people_list(lst):
 @register.filter
 def people_image(person):
     nobody = settings.STATIC_URL + "img/nobody.png"
-    if person.avatar_service:
+    if person and person.avatar_service:
         digest = hashlib.md5(person.email.lower().encode("utf-8")).hexdigest()
         url = AVATAR_SERVICES[person.avatar_service].format(
             hash=digest,
@@ -36,7 +36,7 @@ def people_image(person):
         tag = format_html(
             '<img class="img-circle" src="{url}" alt="{alt}" crossorigin="anonymous">', url=url, 
alt=_("avatar icon")
         )
-    elif person.image:
+    elif person and person.image:
         tag = format_html(
             '<img class="img-circle" src="{}" alt="{}" onerror="this.onerror = null; this.src=\'{}\'">',
             person.image, person.name, nobody
diff --git a/templates/vertimus/vertimus_detail.html b/templates/vertimus/vertimus_detail.html
index 19ee8857..6b43c880 100644
--- a/templates/vertimus/vertimus_detail.html
+++ b/templates/vertimus/vertimus_detail.html
@@ -192,7 +192,11 @@ $(document).ready(function() {
   <div class="vertimus_action">
     <div class="vertimus_action_head">
       <div class="face_image">{{ action.person|people_image }}</div>
-      <a href="{{ action.person.get_absolute_url }}">{{ action.person.name }}</a><br>
+      {% if action.person %}
+        <a href="{{ action.person.get_absolute_url }}">{{ action.person.name }}</a><br>
+      {% else %}
+        <em>{% trans "deleted account" %}</em><br>
+      {% endif %}
       {% if action.file or action.comment %}
       <a name="{{ action.id }}" href="#{{ action.id }}" title="{% trans 'Link to this comment' %}">
           <img alt="link comment icon" class="action_icons" src="{{ STATIC_URL }}img/share.png">
diff --git a/vertimus/migrations/0008_actions_on_delete_setnull.py 
b/vertimus/migrations/0008_actions_on_delete_setnull.py
new file mode 100644
index 00000000..63815923
--- /dev/null
+++ b/vertimus/migrations/0008_actions_on_delete_setnull.py
@@ -0,0 +1,22 @@
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('people', '__first__'),
+        ('vertimus', '0006_pofile_path_relative'),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name='action',
+            name='person',
+            field=models.ForeignKey(null=True, on_delete=models.deletion.SET_NULL, to='people.person'),
+        ),
+        migrations.AlterField(
+            model_name='actionarchived',
+            name='person',
+            field=models.ForeignKey(null=True, on_delete=models.deletion.SET_NULL, to='people.person'),
+        ),
+    ]
diff --git a/vertimus/models.py b/vertimus/models.py
index 3dc51eda..d1c983f3 100644
--- a/vertimus/models.py
+++ b/vertimus/models.py
@@ -348,7 +348,7 @@ class MergedPoFile(PoFile):
 class ActionAbstract(models.Model):
     """ Common model for Action and ActionArchived """
     state_db = models.ForeignKey(State, on_delete=models.CASCADE)
-    person = models.ForeignKey(Person, on_delete=models.CASCADE)
+    person = models.ForeignKey(Person, null=True, on_delete=models.SET_NULL)
 
     name = models.SlugField(max_length=8)
     created = models.DateTimeField(editable=False)
@@ -430,7 +430,7 @@ class ActionAbstract(models.Model):
                     file_history.insert(0, {
                         'action_id': action.id,
                         'title': gettext("Uploaded file by %(name)s on %(date)s") % {
-                            'name': action.person.name,
+                            'name': action.person.name if action.person else gettext('deleted account'),
                             'date': action.created},
                         })
         return history