采购订单维护--修订-控制数量为负时，max取0

src/views/purchase/purchase-order/edit/index.vue

@@ -642,7 +642,8 @@ export default {
 
       if(key === 'qty'){
 
-        return this.handleIsRevise() ? row['originalQty'] :
+        return this.handleIsRevise() ? 
+          (Math.sign(row['originalQty']) == -1 ? 0 : row['originalQty'] ) :
           (this.params.source == '3' ? Infinity: row['originalQty'])
       
       }