Fix vector of table with naked ptr (#8830)

* create test that fails to compile

* fix the issue

* add test body

* force commit gneerated header

* build failures

* fix bazel some more

tests/vector_table_naked_ptr_test.cpp

@@ -0,0 +1,75 @@
+#include "vector_table_naked_ptr_test.h"
+
+#include "test_assert.h"
+#include "vector_table_naked_ptr/vector_table_naked_ptr_generated.h"
+
+namespace flatbuffers {
+namespace tests {
+
+void VectorTableNakedPtrTest() {
+  // ---------------------------------------
+  // 1) Build original native objects
+  // ---------------------------------------
+  auto* b1 = new BT();
+  auto* b2 = new BT();
+  b1->id = 777;
+  b2->id = 888;
+
+  AT a_src;
+  a_src.b.push_back(b1);
+  a_src.b.push_back(b2);
+
+  // ---------------------------------------
+  // 2) Pack into FlatBuffer
+  // ---------------------------------------
+  flatbuffers::FlatBufferBuilder fbb;
+  auto a_offset = A::Pack(fbb, &a_src);
+  FinishABuffer(fbb, a_offset);
+
+  const void* buf = fbb.GetBufferPointer();
+  const A* a_fb = GetA(buf);
+
+  // ---------------------------------------
+  // 3) Pre-allocate destination with garbage
+  // ---------------------------------------
+  AT a_dst;
+
+  // Pre-fill with wrong pointers to ensure UnPackTo overwrites correctly
+  a_dst.b.resize(2);
+  a_dst.b[0] = new BT();
+  a_dst.b[1] = new BT();
+  a_dst.b[0]->id = -1;
+  a_dst.b[1]->id = -1;
+
+  // ---------------------------------------
+  // 4) Call the function under test: UnPackTo
+  // ---------------------------------------
+  a_fb->UnPackTo(&a_dst, nullptr);
+
+  // ---------------------------------------
+  // 5) Validate overwrite + deep copy
+  // ---------------------------------------
+  TEST_ASSERT(a_dst.b.size() == 2);
+
+  TEST_ASSERT(a_dst.b[0] != nullptr);
+  TEST_ASSERT(a_dst.b[1] != nullptr);
+
+  TEST_ASSERT(a_dst.b[0]->id == 777);
+  TEST_ASSERT(a_dst.b[1]->id == 888);
+
+  // Ensure original pointers were not reused
+  TEST_ASSERT(a_dst.b[0] != b1);
+  TEST_ASSERT(a_dst.b[1] != b2);
+
+  // ---------------------------------------
+  // 6) Clean up ownership
+  // ---------------------------------------
+  delete a_dst.b[0];
+  delete a_dst.b[1];
+
+  delete b1;
+  delete b2;
+}
+
+}  // namespace tests
+}  // namespace flatbuffers