From f5ab24bc41b257b95945b75c61f411e3ab0e40c0 Mon Sep 17 00:00:00 2001
From: Ruslan Burakov <kuddai92@yandex.ru>
Date: Thu, 10 Sep 2020 23:03:15 +0300
Subject: [PATCH] Avoid memcpy call for empty vectors (#6111)

Co-authored-by: kuddai <kuddai92@gmail.com>
---
 include/flatbuffers/flatbuffers.h | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/include/flatbuffers/flatbuffers.h b/include/flatbuffers/flatbuffers.h
index 47d6f1b98..12ab68af5 100644
--- a/include/flatbuffers/flatbuffers.h
+++ b/include/flatbuffers/flatbuffers.h
@@ -1607,6 +1607,9 @@ class FlatBufferBuilder {
     // causing the wrong overload to be selected, remove it.
     AssertScalarT<T>();
     StartVector(len, sizeof(T));
+    if (len == 0) {
+      return Offset<Vector<T>>(EndVector(len));
+    }
     // clang-format off
     #if FLATBUFFERS_LITTLEENDIAN
       PushBytes(reinterpret_cast<const uint8_t *>(v), len * sizeof(T));