Exception when reading an array of variants

[bearpaws]

Description

With client-v2, reading a column of type Array(Variant(...)) produces an exception if the array contains values of varying types.

Steps to reproduce

CREATE TABLE test
(
  key String,
  val Array(Variant(Bool,String))
)
ENGINE = MergeTree
ORDER BY (key);

INSERT INTO test VALUES ('a', [true, true]);
INSERT INTO test VALUES ('b', [true, 'z']);

Client client = new Client.Builder()
  .addEndpoint("http://localhost:8123/")
  .setUsername("user")
  .setPassword("pass")
  .build();

TableSchema schema = new TableSchema(List.of(ClickHouseColumn.of("val", "Array(Variant(Bool,String))")));
QuerySettings settings = new QuerySettings().setFormat(ClickHouseFormat.RowBinary);

// Array contains all of same type - this succeeds.
QueryResponse response1 = client.query("select val from test where key='a'", settings).get();
ClickHouseBinaryFormatReader reader1 = client.newBinaryFormatReader(response1, schema);
reader1.next();
List<Object> val = reader1.getList(1);

// Array contains varying types - this fails.
QueryResponse response2 = client.query("select val from test where key='b'", settings).get();
ClickHouseBinaryFormatReader reader2 = client.newBinaryFormatReader(response2, schema);
reader2.next();

Error Log or Exception StackTrace

Exception in thread "main" com.clickhouse.client.api.ClientException: Failed to read value for column val
	at com.clickhouse.client.api.data_formats.internal.BinaryStreamReader.readValue(BinaryStreamReader.java:259)
	at com.clickhouse.client.api.data_formats.internal.BinaryStreamReader.readValue(BinaryStreamReader.java:90)
	at com.clickhouse.client.api.data_formats.internal.AbstractBinaryFormatReader.readRecord(AbstractBinaryFormatReader.java:179)
	at com.clickhouse.client.api.data_formats.internal.AbstractBinaryFormatReader.readNextRecord(AbstractBinaryFormatReader.java:224)
	at com.clickhouse.client.api.data_formats.RowBinaryFormatReader.<init>(RowBinaryFormatReader.java:23)
	at com.clickhouse.client.api.Client.newBinaryFormatReader(Client.java:1982)
	at com.example.Test.main(Test.java:28)
Caused by: java.lang.IllegalArgumentException: Failed to set value at index: 1 value b of class java.lang.String
	at com.clickhouse.client.api.data_formats.internal.BinaryStreamReader$ArrayValue.set(BinaryStreamReader.java:699)
	at com.clickhouse.client.api.data_formats.internal.BinaryStreamReader.readArrayItem(BinaryStreamReader.java:651)
	at com.clickhouse.client.api.data_formats.internal.BinaryStreamReader.readArray(BinaryStreamReader.java:612)
	at com.clickhouse.client.api.data_formats.internal.BinaryStreamReader.readValue(BinaryStreamReader.java:235)
	... 6 more
Caused by: java.lang.IllegalArgumentException: argument type mismatch
	at java.base/java.lang.reflect.Array.set(Native Method)
	at com.clickhouse.client.api.data_formats.internal.BinaryStreamReader$ArrayValue.set(BinaryStreamReader.java:696)
	... 9 more

Expected Behaviour

Read and return the column value as List<Object>.

Configuration

Environment

• Client version: 0.9.2
• Language version: Java 21

ClickHouse Server

• ClickHouse Server version: 25.6.8.10
• ClickHouse Server non-default settings, if any:

[chernser]

@bearpaws
Thank you for reporting the issue!