fix(editor): Fix phantom items for waiting nodes (no-changelog) (#15410)

packages/frontend/editor-ui/src/stores/workflows.store.test.ts

@@ -659,6 +659,56 @@ describe('useWorkflowsStore', () => {
 			});
 		});
 
+		it('should replace placeholder task data in waiting nodes correctly', () => {
+			const runWithExistingRunData = deepCopy(executionResponse);
+			runWithExistingRunData.data = {
+				resultData: {
+					runData: {
+						[successEvent.nodeName]: [
+							{
+								hints: [],
+								startTime: 1727867966633,
+								executionIndex: 2,
+								executionTime: 1,
+								source: [],
+								executionStatus: 'waiting',
+								data: {
+									main: [
+										[
+											{
+												json: {},
+												pairedItem: {
+													item: 0,
+												},
+											},
+										],
+									],
+								},
+							},
+						],
+					},
+				},
+			};
+			workflowsStore.setWorkflowExecutionData(runWithExistingRunData);
+
+			workflowsStore.nodesByName[successEvent.nodeName] = mock<INodeUi>({
+				type: 'n8n-nodes-base.manualTrigger',
+			});
+
+			// ACT
+			workflowsStore.updateNodeExecutionData(successEvent);
+
+			expect(workflowsStore.workflowExecutionData).toEqual({
+				...runWithExistingRunData,
+				data: {
+					resultData: {
+						runData: {
+							[successEvent.nodeName]: [successEvent.data],
+						},
+					},
+				},
+			});
+		});
 		it('should replace existing placeholder task data in new log view', () => {
 			settingsStore.settings = {
 				logsView: {

packages/frontend/editor-ui/src/stores/workflows.store.ts

@@ -1567,7 +1567,11 @@ export const useWorkflowsStore = defineStore(STORES.WORKFLOWS, () => {
 			const existingRunIndex = tasksData.findIndex(
 				(item) => item.executionIndex === data.executionIndex,
 			);
-			const index = existingRunIndex > -1 ? existingRunIndex : tasksData.length - 1;
+
+			// For waiting nodes always replace the last item as executionIndex will always be different
+			const hasWaitingItems = tasksData.some((it) => it.executionStatus === 'waiting');
+			const index =
+				existingRunIndex > -1 && !hasWaitingItems ? existingRunIndex : tasksData.length - 1;
 			const status = tasksData[index]?.executionStatus ?? 'unknown';
 
 			if ('waiting' === status || (settingsStore.isNewLogsEnabled && 'running' === status)) {