fix: handle deleted node during dispatch (baserow#5051)

* Ensure dispatch does crash when node doesn't exist.

* Improve logger message when node doesn't exist.

Author: paljort

backend/src/baserow/contrib/automation/nodes/handler.py

@@ -424,12 +424,27 @@ def dispatch_node(
             logger.error(str(e))
             return None
 
-        node = self.get_node(node_id)
-        simulate_until_node = (
-            node.workflow.get_graph().get_node(workflow_history.simulate_until_node_id)
-            if workflow_history.simulate_until_node_id
-            else None
+        error = (
+            "Node with ID {} was not found. The node was likely "
+            "deleted before the task was executed."
         )
+        try:
+            node = self.get_node(node_id)
+        except AutomationNodeDoesNotExist:
+            logger.warning(error.format(node_id))
+            return None
+
+        try:
+            simulate_until_node = (
+                node.workflow.get_graph().get_node(
+                    workflow_history.simulate_until_node_id
+                )
+                if workflow_history.simulate_until_node_id
+                else None
+            )
+        except AutomationNodeDoesNotExist:
+            logger.warning(error.format(workflow_history.simulate_until_node_id))
+            return None
 
         if simulate_until_node:
             allowed_nodes = {

backend/tests/baserow/contrib/automation/nodes/test_node_dispatch_async.py

@@ -1456,3 +1456,29 @@ def test_dispatch_node_iterator_with_no_rows(data_fixture):
     # Ensure we never return an empty chain, which would cause
     # self.replace() to crash with an error.
     assert result is None
+
+
+@pytest.mark.django_db
+@patch(f"{NODE_HANDLER_PATH}.logger")
+def test_dispatch_node_with_deleted_node(mock_logger, data_fixture):
+    """
+    In the rare case where a node is deleted between the time a dispatch
+    is queued and when the task actually runs, we should handle this
+    gracefully instead of crashing.
+    """
+
+    data = create_workflow(data_fixture)
+    action_node = data["action_node"]
+    history = data["workflow_history"]
+
+    # delete the node to simulate a race condition
+    action_node_id = action_node.id
+    action_node.delete()
+
+    result = AutomationNodeHandler().dispatch_node(action_node_id, history.id)
+    assert result is None
+    expected_error = (
+        f"Node with ID {action_node_id} was not found. The node was likely "
+        "deleted before the task was executed."
+    )
+    mock_logger.warning.assert_called_once_with(expected_error)

changelog/entries/unreleased/bug/fixed_a_bug_that_caused_a_crash_due_to_a_race_condition_that.json

@@ -0,0 +1,9 @@
+{
+    "type": "bug",
+    "message": "Fixed a bug that caused a crash due to a race condition that could happen if a node is deleted while it is being dispatched.",
+    "issue_origin": "github",
+    "issue_number": null,
+    "domain": "automation",
+    "bullet_points": [],
+    "created_at": "2026-03-26"
+}