fix: 404 instead of a hollow 200 when a global view does not exist

Review catch, verified before fixing. WorkspaceViewViewSet.retrieve resolves the
view with .first() and serialized the result unconditionally, so a member asking
for an id that does not exist got 200 with every field null or empty
(`{"name": "", "description": "", "filters": null, ...}`) and a recent-visit
enqueued for a nonexistent entity. Because get_queryset() is scoped to the URL
workspace, the same happened for a real view id belonging to a different
workspace.

Returns 404, matching the other retrieve endpoints.

Noted while confirming this, not fixed here: the project-level sibling
IssueViewViewSet.retrieve has the same .first() pattern and then dereferences
`issue_view.owned_by`, which raises AttributeError on None rather than answering
404 — a 500 instead of a hollow 200. Different method, so it gets its own ticket
rather than widening this one.

Co-authored-by: Plane AI <noreply@plane.so>

apps/api/plane/app/views/view/base.py

@@ -129,6 +129,18 @@ class WorkspaceViewViewSet(BaseViewSet):
         # membership in the workspace could therefore read any global view in it
         # by id.
         issue_view = self.get_queryset().filter(pk=pk).first()
+
+        # get_queryset() is scoped to the URL workspace, so None means either no
+        # such view or one belonging to a workspace this URL does not name.
+        # Serializing None yields a hollow object — every field null or empty —
+        # returned as 200, and enqueues a recent-visit for an entity that does
+        # not exist. Answer 404, as the other retrieve endpoints do.
+        if issue_view is None:
+            return Response(
+                {"error": "The required object does not exist."},
+                status=status.HTTP_404_NOT_FOUND,
+            )
+
         serializer = IssueViewSerializer(issue_view)
         recent_visited_task.delay(
             slug=slug,

apps/api/plane/tests/contract/app/test_undecorated_action_authz_app.py

@@ -249,6 +249,20 @@ class TestWorkspaceViewRetrieveRequiresMembership:
         )
         assert str(response.data["id"]) == str(workspace_view.id)
 
+    @pytest.mark.django_db
+    def test_missing_view_is_a_404_not_an_empty_200(self, session_client, workspace):
+        """A member asking for a view id that does not exist must get 404.
+
+        get_queryset() is scoped to the URL workspace, so this also covers a real
+        view id belonging to a different workspace.
+        """
+        url = WORKSPACE_VIEW_DETAIL_URL.format(slug=workspace.slug, pk=uuid4())
+        response = session_client.get(url)
+
+        assert response.status_code == status.HTTP_404_NOT_FOUND, (
+            f"Got {response.status_code}: {getattr(response, 'data', None)!r}"
+        )
+
     @pytest.mark.django_db
     def test_workspace_guest_can_read_a_global_view(self, workspace, workspace_view):
         """Positive control: the role set matches list(), which permits guests."""