Arrow schema from bytes doesn't handle empty children arrays consistently with python #250
Description
Describe the bug
Found by @gangliao on apache/arrow#9764
reading the code, it does appear that the intent of the ipc::convert::tests::schema_from_bytes test is to compare the schema from two different IPC message (aka schema2 should be coming from the ipc2 message) as @gangliao has done in apache/arrow#9764.
The test seems to have failed however https://github.com/apache/arrow/pull/9764/checks?check_run_id=2161212421
thread 'ipc::convert::tests::schema_from_bytes' panicked at 'assertion failed: `(left == right)`
left: `Schema { endianness: Little, fields: Some([Field { name: Some("field1"), nullable: false, type_type: Int, type_: Int { bitWidth: 32, is_signed: false }, dictionary: None, children: Some([]), custom_metadata: None }]), custom_metadata: None, features: None }`,
right: `Schema { endianness: Little, fields: Some([Field { name: Some("field1"), nullable: false, type_type: Int, type_: Int { bitWidth: 32, is_signed: false }, dictionary: None, children: None, custom_metadata: None }]), custom_metadata: Some([]), features: None }`', arrow/src/ipc/convert.rs:864:9
The difference is that schema has children: Some([]) and schema2 has children: None
To Reproduce
See change to test above
Expected behavior
Test should pass (the schemas should be the same)