v8: fix offsets for TypedArray deserialization

Fix the offset calculation for deserializing TypedArrays that are
not aligned in their original buffer.

Since `byteOffset` refers to the offset into the source `Buffer`
instance, not its underlying `ArrayBuffer`, that is what should
be passed to `buffer.copy`.

PR-URL: https://github.com/nodejs/node/pull/12143
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: James M Snell <jasnell@gmail.com>

1 files changed, 2 insertions, 1 deletions

diff --git a/lib/v8.js b/lib/v8.js
index 7790f9b334..4205552b7d 100644
--- a/lib/v8.js
+++ b/lib/v8.js
@@ -177,7 +177,8 @@ class DefaultDeserializer extends Deserializer {
     } else {
       // Copy to an aligned buffer first.
       const copy = Buffer.allocUnsafe(byteLength);
-      bufferBinding.copy(this.buffer, copy, 0, offset, offset + byteLength);
+      bufferBinding.copy(this.buffer, copy, 0,
+                         byteOffset, byteOffset + byteLength);
       return new ctor(copy.buffer,
                       copy.byteOffset,
                       byteLength / BYTES_PER_ELEMENT);