fix(return): replay concurrent merges and extend integrity acceptance

lastleg-service/src/main/java/com/baiyue/lastleg/returnreceipt/mapper/ReturnInventoryCartonMapper.java

@@ -32,6 +32,9 @@ public interface ReturnInventoryCartonMapper extends BaseMapper<ReturnInventoryC
     @Select("SELECT * FROM ll_return_inventory_carton WHERE carton_mark=#{cartonMark} LIMIT 1 FOR UPDATE")
     ReturnInventoryCarton lockMark(@Param("cartonMark") String cartonMark);
 
+    @Select("SELECT * FROM ll_return_inventory_carton WHERE id=#{id} FOR UPDATE")
+    ReturnInventoryCarton lockId(@Param("id") long id);
+
     @Select("SELECT * FROM ll_return_inventory_carton WHERE source_receipt_id=#{receiptId} LIMIT 1")
     ReturnInventoryCarton findReceipt(@Param("receiptId") long receiptId);
 

lastleg-service/src/main/java/com/baiyue/lastleg/returnreceipt/mapper/ReturnInventoryOperationMapper.java

@@ -10,4 +10,7 @@ import org.apache.ibatis.annotations.Select;
 public interface ReturnInventoryOperationMapper extends BaseMapper<ReturnInventoryOperation> {
     @Select("SELECT * FROM ll_return_inventory_operation WHERE operator_id=#{operatorId} AND idempotency_key=#{key} LIMIT 1")
     ReturnInventoryOperation findKey(@Param("operatorId") String operatorId, @Param("key") String key);
+
+    @Select("SELECT * FROM ll_return_inventory_operation WHERE operator_id=#{operatorId} AND idempotency_key=#{key} LIMIT 1 FOR UPDATE")
+    ReturnInventoryOperation lockKey(@Param("operatorId") String operatorId, @Param("key") String key);
 }

lastleg-service/src/main/java/com/baiyue/lastleg/returnreceipt/service/ReturnInventoryService.java

@@ -224,7 +224,8 @@ public class ReturnInventoryService {
         operation.setRequestHash(requestHash); operation.setOperationType("MERGE"); operation.setCreatedAt(now); operation.setUpdatedAt(now);
         try { operations.insert(operation); }
         catch (DuplicateKeyException concurrent) {
-            ReturnInventoryOperation existing = operations.findKey(identity.operatorKey(), key);
+            // The duplicate insert waited for the winner; the earlier snapshot cannot see its commit.
+            ReturnInventoryOperation existing = operations.lockKey(identity.operatorKey(), key);
             if (existing != null) return replayMerge(existing, requestHash);
             throw concurrent;
         }
@@ -342,14 +343,19 @@ public class ReturnInventoryService {
     private ReturnInventoryResponses.MergeResult replayMerge(ReturnInventoryOperation operation, String requestHash) {
         if (!requestHash.equals(operation.getRequestHash())) throw conflict("幂等键已用于不同的合箱请求");
         if (operation.getResultCartonId() == null) throw conflict("合箱请求正在处理");
-        ReturnInventoryCarton carton = cartons.selectById(operation.getResultCartonId());
+        // The result and its label must also bypass the snapshot established before the insert race.
+        ReturnInventoryCarton carton = cartons.lockId(operation.getResultCartonId());
         if (carton == null) throw new IllegalStateException("合箱结果箱不存在");
-        List<ReturnInventoryCartonItem> items = cartonItems.listCarton(carton.getId());
-        return new ReturnInventoryResponses.MergeResult(carton.getCartonMark(), items.get(0).getSkuCode(), carton.getTotalQuantity(), label(carton));
+        List<ReturnInventoryCartonItem> items = cartonItems.lockCarton(carton.getId());
+        return new ReturnInventoryResponses.MergeResult(carton.getCartonMark(), items.get(0).getSkuCode(), carton.getTotalQuantity(), label(carton, items));
     }
 
     private ReturnInventoryResponses.Label label(ReturnInventoryCarton carton) {
-        List<ReturnInventoryResponses.CartonItem> items = cartonItems.listCarton(carton.getId()).stream()
+        return label(carton, cartonItems.listCarton(carton.getId()));
+    }
+
+    private ReturnInventoryResponses.Label label(ReturnInventoryCarton carton, List<ReturnInventoryCartonItem> cartonLines) {
+        List<ReturnInventoryResponses.CartonItem> items = cartonLines.stream()
             .map(item -> new ReturnInventoryResponses.CartonItem(item.getSkuCode(), item.getProductNameZh(), item.getQuantity())).toList();
         return new ReturnInventoryResponses.Label(carton.getCartonMark(), carton.getOverseasWarehouseId(), carton.getCustomerId(),
             carton.getSourceBatchNo(), carton.getSourceReturnNo(), value(carton.getTotalQuantity()), carton.getLength(), carton.getWidth(), carton.getHeight(), carton.getWeight(), items, LocalDateTime.now(), printableHtml(carton, items));