Fixed bug with sparse global order writes when the buffer sizes are zero

PR #1248

(cherry picked from commit df093f1)

test/src/unit-capi-sparse_array.cc

@@ -2770,4 +2770,61 @@ TEST_CASE_METHOD(
     check_sorted_reads(
         array_name, TILEDB_FILTER_BZIP2, TILEDB_ROW_MAJOR, TILEDB_COL_MAJOR);
   }
-}
+}
+
+TEST_CASE_METHOD(
+    SparseArrayFx,
+    "C API: Test sparse array, global order with 0-sized buffers",
+    "[capi][sparse][global-check][zero-buffers]") {
+  std::string array_name =
+      FILE_URI_PREFIX + FILE_TEMP_DIR + "sparse_write_global_check";
+  create_sparse_array(array_name);
+
+  // Create TileDB context
+  tiledb_ctx_t* ctx = nullptr;
+  REQUIRE(tiledb_ctx_alloc(nullptr, &ctx) == TILEDB_OK);
+
+  // Open array
+  tiledb_array_t* array;
+  int rc = tiledb_array_alloc(ctx, array_name.c_str(), &array);
+  CHECK(rc == TILEDB_OK);
+  rc = tiledb_array_open(ctx, array, TILEDB_WRITE);
+  CHECK(rc == TILEDB_OK);
+
+  // Create WRITE query
+  tiledb_query_t* query;
+  rc = tiledb_query_alloc(ctx, array, TILEDB_WRITE, &query);
+  CHECK(rc == TILEDB_OK);
+  rc = tiledb_query_set_layout(ctx, query, TILEDB_GLOBAL_ORDER);
+  CHECK(rc == TILEDB_OK);
+
+  // Prepare attribute buffers
+  int a1[1];
+  char a2[1];
+  uint64_t a2_off[1];
+  float a3[1];
+  uint64_t coords[1];
+  uint64_t zero_size = 0;
+
+  // Set buffers with zero size
+  rc = tiledb_query_set_buffer(ctx, query, "a1", a1, &zero_size);
+  CHECK(rc == TILEDB_OK);
+  rc = tiledb_query_set_buffer_var(
+      ctx, query, "a2", a2_off, &zero_size, a2, &zero_size);
+  CHECK(rc == TILEDB_OK);
+  rc = tiledb_query_set_buffer(ctx, query, "a3", a3, &zero_size);
+  CHECK(rc == TILEDB_OK);
+  rc = tiledb_query_set_buffer(ctx, query, TILEDB_COORDS, coords, &zero_size);
+  CHECK(rc == TILEDB_OK);
+
+  // Submit query
+  CHECK(tiledb_query_submit(ctx, query) == TILEDB_OK);
+
+  // Close array
+  CHECK(tiledb_array_close(ctx, array) == TILEDB_OK);
+
+  // Clean up
+  tiledb_query_free(&query);
+  tiledb_array_free(&array);
+  tiledb_ctx_free(&ctx);
+}

tiledb/sm/query/writer.cc

@@ -428,6 +428,9 @@ Status Writer::check_coord_dups(const std::vector<uint64_t>& cell_pos) const {
   auto coords_size = array_schema_->coords_size();
   auto coords_num = cell_pos.size();
 
+  if (coords_num < 2)
+    return Status::Ok();
+
   for (uint64_t i = 1; i < coords_num; ++i) {
     if (!memcmp(
             coords_buff + cell_pos[i] * coords_size,
@@ -456,6 +459,9 @@ Status Writer::check_coord_dups() const {
   auto coords_size = array_schema_->coords_size();
   auto coords_num = coords_buff_size / coords_size;
 
+  if (coords_num < 2)
+    return Status::Ok();
+
   for (uint64_t i = 1; i < coords_num; ++i) {
     if (!memcmp(
             coords_buff + i * coords_size,
@@ -526,6 +532,9 @@ Status Writer::check_coord_oob() const {
   auto dim_num = array_schema_->dim_num();
   auto domain = (T*)array_schema_->domain()->domain();
 
+  if (coords_num == 0)
+    return Status::Ok();
+
   // Check if all coordinates fall in the domain in parallel
   auto statuses = parallel_for(0, coords_num, [&](uint64_t i) {
     if (!utils::geometry::coords_in_rect<T>(
@@ -609,6 +618,9 @@ Status Writer::check_global_order() const {
   auto dim_num = array_schema_->dim_num();
   auto domain = array_schema_->domain();
 
+  if (coords_num < 2)
+    return Status::Ok();
+
   // Check if all coordinates fall in the domain in parallel
   auto statuses = parallel_for(0, coords_num - 1, [&](uint64_t i) {
     auto tile_cmp = domain->tile_order_cmp<T>(