From 5235133f321b71f041b515002d3c8f7049f497de Mon Sep 17 00:00:00 2001
From: Ivan Dlugos <6349682+vaind@users.noreply.github.com>
Date: Thu, 29 Jul 2021 19:39:03 +0200
Subject: [PATCH] Dart - make ascii optimization optional in StringReader, same
 as in writeString() (#6758)

---
 dart/lib/flat_buffers.dart       | 11 ++++++-----
 dart/test/flat_buffers_test.dart |  2 +-
 2 files changed, 7 insertions(+), 6 deletions(-)

diff --git a/dart/lib/flat_buffers.dart b/dart/lib/flat_buffers.dart
index 500228576..5b85a7bf9 100644
--- a/dart/lib/flat_buffers.dart
+++ b/dart/lib/flat_buffers.dart
@@ -1033,20 +1033,21 @@ abstract class Reader<T> {
 
 /// The reader of string values.
 class StringReader extends Reader<String> {
-  const StringReader() : super();
+  final bool asciiOptimization;
+  const StringReader({this.asciiOptimization = false}) : super();
 
   @override
   @pragma('vm:prefer-inline')
-  int get size => 4;
+  int get size => _sizeofUint32;
 
   @override
   @pragma('vm:prefer-inline')
   String read(BufferContext bc, int offset) {
     int strOffset = bc.derefObject(offset);
     int length = bc._getUint32(strOffset);
-    Uint8List bytes = bc._asUint8List(strOffset + 4, length);
-    if (_isLatin(bytes)) {
-      return new String.fromCharCodes(bytes);
+    Uint8List bytes = bc._asUint8List(strOffset + _sizeofUint32, length);
+    if (asciiOptimization && _isLatin(bytes)) {
+      return String.fromCharCodes(bytes);
     }
     return utf8.decode(bytes);
   }
diff --git a/dart/test/flat_buffers_test.dart b/dart/test/flat_buffers_test.dart
index 6d595698e..050c477c6 100644
--- a/dart/test/flat_buffers_test.dart
+++ b/dart/test/flat_buffers_test.dart
@@ -379,7 +379,7 @@ class BuilderTest {
             .vTableGetNullable(buf, objectOffset, indexToField(0)),
         latinString);
     expect(
-        const StringReader()
+        const StringReader(asciiOptimization: true)
             .vTableGetNullable(buf, objectOffset, indexToField(1)),
         unicodeString);
   }