[beduldul]

Description

Two input-handling bugs in telebot/util.py.

smart_split appends an empty part. It compared with <, so any text whose length is an exact multiple of chars_per_string went through the split path one last time on the remainder and appended '':

>>> smart_split("abc", 3)
['abc', '']          # expected ['abc']

>>> smart_split("a" * 4096)
['a'*4096, '']       # a full-length message

Sending that empty part to Telegram fails with Bad Request: message text is empty. Changed to <=, which covers every multiple, not just the 4096 case.

extract_arguments raises on None. It compiled the regexp and matched before checking the argument, so a non-text message (message.text is None) raised TypeError. is_command and extract_command already tolerate None, so this now matches them.

>>> extract_arguments(None)
TypeError: expected string or bytes-like object, got 'NoneType'

Describe your tests

Added tests/test_util.py — smart_split had no coverage at all. It walks exact multiples across several chunk sizes, checks the newline/space preference, the 4096 cap, and the None handling plus the normal extract_arguments cases.

Full suite: 314 passed, 73 skipped.

Python version: 3.12.3

OS: macOS 27.2

Checklist:

• I added/edited example on new feature/change (if exists)
• My changes won't break backward compatibility
• I made changes both for sync and async