From 6e12aa4bf78a3bd4df342b5b6d4f569d2a8c1463 Mon Sep 17 00:00:00 2001
From: John Guo <john@johng.cn>
Date: Thu, 13 Jan 2022 20:49:26 +0800
Subject: [PATCH] fix issue #1568

---
 util/gconv/gconv_map.go | 24 ++++++++++++++----------
 1 file changed, 14 insertions(+), 10 deletions(-)

diff --git a/util/gconv/gconv_map.go b/util/gconv/gconv_map.go
index f448a8d6b..3c2093283 100644
--- a/util/gconv/gconv_map.go
+++ b/util/gconv/gconv_map.go
@@ -217,23 +217,25 @@ func doMapConvertForMapOrStructValue(isRoot bool, value interface{}, recursive b
 		return dataMap
 
 	case reflect.Struct:
+		var dataMap = make(map[string]interface{})
 		// Map converting interface check.
 		if v, ok := value.(iMapStrAny); ok {
-			m := v.MapStrAny()
-			if recursive {
-				for k, v := range m {
-					m[k] = doMapConvertForMapOrStructValue(false, v, recursive, tags...)
+			// Value copy, in case of concurrent safety.
+			for mapK, mapV := range v.MapStrAny() {
+				if recursive {
+					dataMap[mapK] = doMapConvertForMapOrStructValue(false, mapV, recursive, tags...)
+				} else {
+					dataMap[mapK] = mapV
 				}
 			}
-			return m
+			return dataMap
 		}
 		// Using reflect for converting.
 		var (
 			rtField     reflect.StructField
 			rvField     reflect.Value
-			dataMap     = make(map[string]interface{}) // result map.
-			reflectType = reflectValue.Type()          // attribute value type.
-			mapKey      = ""                           // mapKey may be the tag name or the struct attribute name.
+			reflectType = reflectValue.Type() // attribute value type.
+			mapKey      = ""                  // mapKey may be the tag name or the struct attribute name.
 		)
 		for i := 0; i < reflectValue.NumField(); i++ {
 			rtField = reflectType.Field(i)
@@ -319,8 +321,10 @@ func doMapConvertForMapOrStructValue(isRoot bool, value interface{}, recursive b
 						break
 					}
 					array := make([]interface{}, length)
-					for i := 0; i < length; i++ {
-						array[i] = doMapConvertForMapOrStructValue(false, rvAttrField.Index(i), recursive, tags...)
+					for arrayIndex := 0; arrayIndex < length; arrayIndex++ {
+						array[arrayIndex] = doMapConvertForMapOrStructValue(
+							false, rvAttrField.Index(arrayIndex), recursive, tags...,
+						)
 					}
 					dataMap[mapKey] = array
 				case reflect.Map: