Merge pull request #6 from spiceai/peasee-patch-2

fix: Don't nullify release callback for schemas

Author: peasee

src/function/table/arrow.cpp

@@ -23,6 +23,9 @@ void ArrowTableFunction::PopulateArrowTableSchema(DBConfig &config, ArrowTableSc
 	vector<string> names;
 	// We first gather the column names and deduplicate them
 	for (idx_t col_idx = 0; col_idx < static_cast<idx_t>(arrow_schema.n_children); col_idx++) {
+		if (arrow_schema.children[col_idx] == nullptr) {
+			throw InvalidInputException("arrow_scan: null schema pointer for column %d", col_idx);
+		}
 		const auto &schema = *arrow_schema.children[col_idx];
 		if (!schema.release) {
 			throw InvalidInputException("arrow_scan: released schema passed");

src/main/capi/arrow-c.cpp

@@ -355,12 +355,6 @@ void EmptyStreamRelease(ArrowArrayStream *stream) {
 
 void FactoryGetSchema(ArrowArrayStream *stream, ArrowSchema &schema) {
 	stream->get_schema(stream, &schema);
-
-	// Need to nullify the root schema's release function here, because streams don't allow us to set the release
-	// function. For the schema's children, we nullify the release functions in `duckdb_arrow_scan`, so we don't need to
-	// handle them again here. We set this to nullptr and not EmptySchemaRelease to prevent ArrowSchemaWrapper's
-	// destructor from destroying the schema (it's the caller's responsibility).
-	schema.release = nullptr;
 }
 
 int GetSchema(struct ArrowArrayStream *stream, struct ArrowSchema *out) {
@@ -370,7 +364,6 @@ int GetSchema(struct ArrowArrayStream *stream, struct ArrowSchema *out) {
 	}
 
 	*out = *private_data->schema;
-	out->release = EmptySchemaRelease;
 	return DuckDBSuccess;
 }
 
@@ -406,7 +399,13 @@ const char *GetLastError(struct ArrowArrayStream *stream) {
 
 void Release(struct ArrowArrayStream *stream) {
 	if (stream->private_data != nullptr) {
-		delete reinterpret_cast<PrivateData *>(stream->private_data);
+		auto private_data = reinterpret_cast<PrivateData *>(stream->private_data);
+		if (private_data->schema && private_data->schema->release) {
+			private_data->schema->release(private_data->schema);
+			private_data->schema = nullptr;
+		}
+
+		delete private_data;
 	}
 
 	stream->private_data = nullptr;