[Bug] UnicodeDecodeError in input thread crashes application when invalid UTF-8 bytes are received

[0x7c13]

Have you checked closed issues? (https://github.com/Textualize/textual/issues?q=is%3Aissue+is%3Aclosed)
Yes

Have you checked against the most recent version of Textual? (https://pypi.org/search/?q=textual)
Yes

The bug

The input threads in LinuxDriver, LinuxInlineDriver, and WebDriver all create a strict UTF-8 incremental decoder:

e.g. linux_driver.py line 414

utf8_decoder = getincrementaldecoder("utf-8")().decode

Since no errors= argument is passed, this defaults to errors="strict". If any invalid UTF-8 byte sequence arrives from the terminal, the decoder raises
UnicodeDecodeError, which propagates up through run_input_thread() and kills the input thread. Once the input thread dies, the application loses all keyboard
and mouse handling and becomes unresponsive.

How to trigger:

• Pasting content from a terminal with a non-UTF-8 locale (e.g. a Latin-1 or GBK encoded terminal)
• Raw binary data leaking into stdin (e.g. from a misbehaving pipe or multiplexer)
• A broken partial paste containing truncated multi-byte sequences

Affected files:

• src/textual/drivers/linux_driver.py (line 414)
• src/textual/drivers/linux_inline_driver.py (line 133)
• src/textual/drivers/web_driver.py (line 188)

Suggested fix:

  # Before (strict — crashes on invalid bytes)
  utf8_decoder = getincrementaldecoder("utf-8")().decode

  # After (replace — substitutes U+FFFD for invalid bytes)
  utf8_decoder = getincrementaldecoder("utf-8")(errors="replace").decode

[github-actions]

We found the following entries in the FAQ which you may find helpful:

• How do I pass arguments to an app?
• How do I fix WorkerDeclarationError?

Feel free to close this issue if you found an answer in the FAQ. Otherwise, please give us a little time to review.

This project is developed and maintained by Will McGugan. Consider sponsoring Will's work on this project (and others).

This is an automated reply, generated by FAQtory