working other than stack imablances

Author: paleolimbot

r/src/materialize.c

@@ -333,7 +333,7 @@ SEXP nanoarrow_materialize_finalize_result(SEXP converter_xptr, SEXP result) {
         Rf_lang4(new_nanoarrow_vctr_sym, chunks_list, schema_xptr, subclass_sexp));
     SEXP final_result = PROTECT(Rf_eval(new_nanoarrow_vctr_call, nanoarrow_ns_pkg));
 
-    UNPROTECT(8);
+    UNPROTECT(6);
     return final_result;
   } else {
     return result;
@@ -345,11 +345,13 @@ static int nanoarrow_materialize_nanoarrow_vctr(struct RConverter* converter,
   // This is a case where the callee needs ownership, which we can do via a
   // shallow copy.
   SEXP converter_shelter = R_ExternalPtrProtected(converter_xptr);
+  SEXP schema_xptr = VECTOR_ELT(converter_shelter, 1);
   SEXP array_xptr = VECTOR_ELT(converter_shelter, 2);
 
   SEXP array_out_xptr = PROTECT(nanoarrow_array_owning_xptr());
-  struct ArrowArray* out_array = nanoarrow_output_array_from_xptr(array_xptr);
+  struct ArrowArray* out_array = nanoarrow_output_array_from_xptr(array_out_xptr);
   array_export(array_xptr, out_array);
+  R_SetExternalPtrTag(array_out_xptr, schema_xptr);
 
   // Get the cached copy of the pairlist node at the end of the current
   // chunks list.

r/tests/testthat/test-convert-array.R

@@ -195,6 +195,27 @@ test_that("convert to vector works for nanoarrow_vctr()", {
   expect_identical(schema$format, "+s")
 })
 
+test_that("batched convert to vector works for nanoarrow_vctr()", {
+  empty_stream <- basic_array_stream(list(), schema = na_string())
+  empty_vctr <- convert_array_stream(empty_stream, nanoarrow_vctr())
+  expect_length(empty_vctr, 0)
+  expect_identical(infer_nanoarrow_schema(empty_vctr)$format, "u")
+
+  stream1 <- basic_array_stream(list(c("one", "two", "three")))
+  vctr1 <- convert_array_stream(stream1, nanoarrow_vctr())
+  expect_length(vctr1, 3)
+
+  stream2 <- basic_array_stream(
+    list(c("one", "two", "three"), c("four", "five", "six", "seven"))
+  )
+  vctr2 <- convert_array_stream(stream2, nanoarrow_vctr())
+  expect_length(vctr2, 7)
+  expect_identical(
+    convert_array_stream(as_nanoarrow_array_stream(vctr2)),
+    c("one", "two", "three", "four", "five", "six", "seven")
+  )
+})
+
 test_that("convert to vector works for struct-style vectors", {
   array <- as_nanoarrow_array(as.POSIXlt("2021-01-01", tz = "America/Halifax"))
   expect_identical(