apacheGH-36913: [C++] Skip empty buffer concatenation to fix UBSan error

sfc-gh-ebrossard · Jul 27, 2023 · 6d25184 · 6d25184
1 parent 0f29147
commit 6d25184
Showing 1 changed file with 5 additions and 2 deletions.
diff --git a/cpp/src/arrow/buffer.cc b/cpp/src/arrow/buffer.cc
@@ -213,8 +213,11 @@ Result<std::shared_ptr<Buffer>> ConcatenateBuffers(
   ARROW_ASSIGN_OR_RAISE(auto out, AllocateBuffer(out_length, pool));
   auto out_data = out->mutable_data();
   for (const auto& buffer : buffers) {
-    std::memcpy(out_data, buffer->data(), buffer->size());
-    out_data += buffer->size();
+    // Passing nullptr to std::memcpy is undefined behavior, so skip empty buffers
+    if (buffer->size() != 0) {
+      std::memcpy(out_data, buffer->data(), buffer->size());
+      out_data += buffer->size();
+    }
   }
   return std::move(out);
 }