fix: stabilize quick win redirects and task ownership

app/routes/tasks.py

@@ -113,6 +113,23 @@ def _redirect_with_celebration(target_url: str, points: int | None = None):
     return redirect(redirect_url)
 
 
+def _safe_referrer_target(fallback: str) -> str:
+    referrer = request.referrer
+    if not referrer:
+        return fallback
+
+    parts = urlsplit(referrer)
+    if parts.netloc and parts.netloc != request.host:
+        return fallback
+
+    query = dict(parse_qsl(parts.query, keep_blank_values=True))
+    query.pop("celebrate_points", None)
+    target = urlunsplit(("", "", parts.path or fallback, urlencode(query), parts.fragment))
+    if not target.startswith("/") or len(target) > 1200:
+        return fallback
+    return target
+
+
 @bp.route("/my-tasks")
 @login_required
 def my_tasks():
@@ -293,7 +310,7 @@ def quick_create():
                     flash(error, "error")
             for error in extra_errors:
                 flash(error, "error")
-            return redirect(request.referrer or url_for("tasks.my_tasks"))
+            return redirect(_safe_referrer_target(url_for("tasks.my_tasks")))
         task = create_quick_task(custom_title, form.effort.data, current_user, description="Quick-Win")
         complete_task(task, current_user.id)
         created_titles.append(task.title)
@@ -301,14 +318,14 @@ def quick_create():
 
     if not created_titles:
         flash("Bitte wähle mindestens einen Quick-Win aus.", "error")
-        return redirect(request.referrer or url_for("tasks.my_tasks"))
+        return redirect(_safe_referrer_target(url_for("tasks.my_tasks")))
 
     if len(created_titles) == 1:
         flash(f"Quick-Win „{created_titles[0]}“ wurde als erledigt gespeichert.", "success")
     else:
         flash(f"{len(created_titles)} Quick-Wins wurden als erledigt gespeichert.", "success")
     return _redirect_with_celebration(
-        request.referrer or url_for("tasks.my_tasks"),
+        _safe_referrer_target(url_for("tasks.my_tasks")),
         total_points,
     )
 
@@ -360,7 +377,7 @@ def complete(task_id: int):
     choice = request.form.get("completed_for", "me")
     if task.is_completed:
         flash("Diese Aufgabe ist bereits erledigt.", "info")
-        return redirect(request.referrer or url_for("tasks.my_tasks"))
+        return redirect(_safe_referrer_target(url_for("tasks.my_tasks")))
 
     completed_by_id = current_user.id
     allowed_ids = {current_user.id}
@@ -377,7 +394,7 @@ def complete(task_id: int):
     complete_task(task, completed_by_id)
     flash("Punkte verbucht. Gute Arbeit.", "success")
     return _redirect_with_celebration(
-        request.referrer or url_for("tasks.my_tasks"),
+        _safe_referrer_target(url_for("tasks.my_tasks")),
         awarded_points,
     )
 

app/services/tasks.py

@@ -66,8 +66,6 @@ def update_template_and_instance(task: TaskInstance, form) -> TaskInstance:
     template.title = form.title.data.strip()
     template.description = (form.description.data or "").strip()
     template.default_points = form.default_points.data
-    template.default_assigned_user_id = form.assigned_user_id.data
-    template.default_assigned_user_secondary_id = form.assigned_user_secondary_id.data or None
     template.recurrence_interval_unit = form.recurrence_interval_unit.data
     template.recurrence_interval_value = (
         form.recurrence_interval_value.data if form.recurrence_interval_unit.data != "none" else None
@@ -76,9 +74,9 @@ def update_template_and_instance(task: TaskInstance, form) -> TaskInstance:
 
     task.title = template.title
     task.description = template.description
-    task.assigned_user_id = template.default_assigned_user_id
+    task.assigned_user_id = form.assigned_user_id.data
-    task.assigned_user_secondary_id = template.default_assigned_user_secondary_id
+    task.assigned_user_secondary_id = form.assigned_user_secondary_id.data or None
-    task.points_awarded = effective_points(template.default_points, template.default_assigned_user_secondary_id)
+    task.points_awarded = effective_points(template.default_points, task.assigned_user_secondary_id)
     task.due_date = form.due_date.data
     refresh_task_status(task, form.due_date.data)
     db.session.commit()

app/templates/tasks/task_form.html

@@ -30,8 +30,15 @@
       </div>
 
       <div class="field">
+        {% if mode == 'edit' %}
+          <label for="{{ form.assigned_user_id.id }}">Zuständig für diese Aufgabe</label>
+        {% else %}
           {{ form.assigned_user_id.label }}
+        {% endif %}
         {{ form.assigned_user_id() }}
+        {% if mode == 'edit' %}
+          <small class="muted">Wiederholungen bleiben bei der ursprünglich vorgesehenen Person.</small>
+        {% endif %}
         {% for error in form.assigned_user_id.errors %}<small class="error">{{ error }}</small>{% endfor %}
       </div>