[Python] segfault when calling nbytes on empty table with dictionary field

[0x26res]

Describe the bug, including details regarding any error messages, version, and platform.

Using pyarrow.Table.nbytes on an empty table with a dictionary field causes a segmentation fault.

import pyarrow as pa

schema = pa.schema(
    [
        pa.field("foo", pa.dictionary(pa.int32(), pa.string())),
    ]
)
table = pa.table({"foo": []}, schema=schema)

print(table.nbytes)  # segmentation fault  python

A few notes:

• get_total_buffer_size works (which is a good workaround for now)
• It works if the table has got one or more row (including nulls)
• It works if the table is empty but there are not dictionary fields
• I'm using pyarrow==11.0.0 and Python 3.9.16 (but it is happening in 10.0.1 as well, so not a new bug)

Component(s)

Python