Use gcc-13 instead of gcc-11 when building in Ubuntu 20.04.

gcc-11 leads to a seg fault in tensormap in Release mode.

cpp/open3d/core/nns/NanoFlannImpl.h

@@ -118,13 +118,6 @@ void _KnnSearchCPU(NanoFlannIndexHolderBase *holder,
  return;
  }
 
- auto points_equal = [](const T *const p1, const T *const p2,
- size_t dimension) {
- std::vector<T> p1_vec(p1, p1 + dimension);
- std::vector<T> p2_vec(p2, p2 + dimension);
- return p1_vec == p2_vec;
- };
-
  std::vector<std::vector<TIndex>> neighbors_indices(num_queries);
  std::vector<std::vector<T>> neighbors_distances(num_queries);
  std::vector<uint32_t> neighbors_count(num_queries, 0);
@@ -147,8 +140,9 @@ void _KnnSearchCPU(NanoFlannIndexHolderBase *holder,
  for (size_t valid_i = 0; valid_i < num_valid; ++valid_i) {
  TIndex idx = result_indices[valid_i];
  if (ignore_query_point &&
- points_equal(&queries[i * dimension],
- &points[idx * dimension], dimension)) {
+ std::equal(&queries[i * dimension],
+ &queries[i * dimension] + dimension,
+ &points[idx * dimension])) {
  continue;
  }
  neighbors_indices[i].push_back(idx);
@@ -222,13 +216,6 @@ void _RadiusSearchCPU(NanoFlannIndexHolderBase *holder,
  return;
  }
 
- auto points_equal = [](const T *const p1, const T *const p2,
- size_t dimension) {
- std::vector<T> p1_vec(p1, p1 + dimension);
- std::vector<T> p2_vec(p2, p2 + dimension);
- return p1_vec == p2_vec;
- };
-
  std::vector<std::vector<TIndex>> neighbors_indices(num_queries);
  std::vector<std::vector<T>> neighbors_distances(num_queries);
  std::vector<uint32_t> neighbors_count(num_queries, 0);
@@ -255,9 +242,9 @@ void _RadiusSearchCPU(NanoFlannIndexHolderBase *holder,
  int num_neighbors = 0;
  for (const auto &idx_dist : search_result) {
  if (ignore_query_point &&
- points_equal(&queries[i * dimension],
-  &points[idx_dist.first * dimension],
-   dimension)) {
+ std::equal(&queries[i * dimension],
+ &queries[i * dimension] + dimension,
+ &points[idx_dist.first * dimension])) {
  continue;
  }
  neighbors_indices[i].push_back(idx_dist.first);

cpp/tests/t/geometry/TensorMap.cpp

@@ -32,6 +32,13 @@ TEST_P(TensorMapPermuteDevices, Constructor) {
  // Primary key is required.
  EXPECT_ANY_THROW(t::geometry::TensorMap());
 
+ // Delete primary key.
+ EXPECT_ANY_THROW(tm0.Erase("positions"));
+
+ // Reserved keys.
+ EXPECT_ANY_THROW(tm0.insert(
+ {"primary_key", core::Tensor::Zeros({2, 3}, dtype, device)}));
+
  // Iterators.
  std::map<std::string, core::Tensor> tensor_map(
  {{"positions", core::Tensor::Zeros({10, 3}, dtype, device)},

docker/Dockerfile.ci

@@ -68,6 +68,8 @@ RUN if [ "${BUILD_SYCL_MODULE}" = "ON" ]; then \
  fi
 
 # Dependencies: basic and python-build
+# gcc-11 causes a seg fault in tensormap when built in Release mode. Upgrade to
+# gcc-13 instead.
 RUN apt-get update && apt-get install -y \
  git \
  wget \
@@ -87,11 +89,16 @@ RUN apt-get update && apt-get install -y \
  libxmlsec1-dev \
  libffi-dev \
  liblzma-dev \
+ && if c++ --version | grep -F ' 11.' ; then \
+ apt-get install -y g++-13 \
+ && update-alternatives --install /usr/bin/c++ c++ /usr/bin/g++-13 100 \
+ && c++ --version; \
+ fi \
  && rm -rf /var/lib/apt/lists/*
 
 # pyenv or Intel Python
 # The pyenv python paths are used during docker run, in this way docker run
-# does not need to activate the environment again. 
+# does not need to activate the environment again.
 # The soft link from the python patch level version to the python mino version
 # ensures python wheel commands (i.e. open3d) are in PATH, since we don't know
 # which patch level pyenv will install (latest).