[Backport] Issue #2916: When leaving a project I lose all my watched stuff (even from different projects)

taiga/projects/signals.py

@@ -19,6 +19,7 @@ from django.conf import settings
 
 from taiga.projects.services.tags_colors import update_project_tags_colors_handler, remove_unused_tags
 from taiga.projects.notifications.services import create_notify_policy_if_not_exists
+from taiga.base.utils.db import get_typename_for_model_class
 
 
 ####################################
@@ -53,7 +54,13 @@ def update_watchers_on_membership_post_delete(sender, instance, using, **kwargs)
     # instance.user can contain pointer to now
     # removed object from a database.
     for model in models:
-        model.watchers.through.objects.filter(user_id=instance.user_id).delete()
+        #filter(project=instance.project)
+        filter = {
+            "user_id": instance.user_id,
+            "%s__project"%(model._meta.model_name): instance.project,
+        }
+
+        model.watchers.through.objects.filter(**filter).delete()
 
 
 def create_notify_policy(sender, instance, using, **kwargs):

tests/integration/test_projects.py

@@ -212,6 +212,22 @@ def test_leave_project_invalid_membership(client):
     assert response.status_code == 404
 
 
+def test_leave_project_respect_watching_items(client):
+    user = f.UserFactory.create()
+    project = f.ProjectFactory.create()
+    role = f.RoleFactory.create(project=project, permissions=["view_project"])
+    f.MembershipFactory.create(project=project, user=user, role=role)
+    issue = f.IssueFactory(owner=user)
+    issue.watchers=[user]
+    issue.save()
+
+    client.login(user)
+    url = reverse("projects-leave", args=(project.id,))
+    response = client.post(url)
+    assert response.status_code == 200
+    assert list(issue.watchers.all()) == [user]
+
+
 def test_delete_membership_only_owner(client):
     user = f.UserFactory.create()
     project = f.ProjectFactory.create()