fix cfug#372

Author: wendux

package_src/CHANGELOG.md

@@ -1,3 +1,7 @@
+# 2.1.13
+
+- fix #369
+
 # 2.1.12
 
 - fix #367 #365

package_src/lib/src/form_data.dart

@@ -102,7 +102,7 @@ class FormData extends MapMixin<String, dynamic> {
     writeMapLength(buf, key, value) {
       value.keys.toList().forEach((mapKey) {
         var nestedKey = '${key}[${mapKey}]';
-        if (value[mapKey]) return;
+        if (value[mapKey]==null) return;
         if (value[mapKey] is Map) {
           writeMapLength(buf, nestedKey, value[mapKey]);
         } else if (value[mapKey] is UploadFileInfo) {

package_src/pubspec.yaml

@@ -1,6 +1,6 @@
 name: dio
 description: A powerful Http client for Dart, which supports Interceptors, FormData, Request Cancellation, File Downloading, Timeout etc.
-version: 2.1.12
+version: 2.1.13
 homepage: https://github.com/flutterchina/dio
 author: wendux <[email protected]>