Fixed an offset error in Node buffer handling (#4826)

CHANGELOG.md

@@ -36,6 +36,7 @@ NOTE: This version is unrelated to the v10.20.0-alpha and v10.20.0-beta prerelea
 * Fixed an incorrect git merge in the Xcode project from RN iOS. ([#4756](https://github.com/realm/realm-js/issues/4756), since v10.19.5)
 * Fixed detection of emulator environments to be more robust.  Thanks to [Ferry Kranenburg](https://github.com/fkranenburg) for identifying the issue and supplying a PR. ([#4784](https://github.com/realm/realm-js/issues/4784))
 * Opening a read-only synced Realm for the first time could lead to `m_schema_version != ObjectStore::NotVersioned` assertion.
+* Fixed an offset error in Node buffer handling ([#3781](https://github.com/realm/realm-js/issues/3781), since v10.0.0)
 
 ### Compatibility
 * React Native >= v0.64.0

src/node/node_buffer.hpp

@@ -48,15 +48,15 @@ auto get_data(ArrayBuffer buffer)
 template <>
 auto get_data<DataView>(DataView data_view)
 {
-    auto buffer = data_view.ArrayBuffer();
-    return static_cast<const char*>(buffer.Data());
+    Napi::ArrayBuffer buffer = data_view.ArrayBuffer();
+    return (static_cast<const char*>(buffer.Data()) + data_view.ByteOffset());
 }
 
 template <>
 auto get_data<TypedArray>(TypedArray typed_array)
 {
-    auto buffer = typed_array.ArrayBuffer();
-    return static_cast<const char*>(buffer.Data());
+    Napi::ArrayBuffer buffer = typed_array.ArrayBuffer();
+    return (static_cast<const char*>(buffer.Data())) + typed_array.ByteOffset();
 }
 
 class NodeBinary {