Problem description

termux seems to fail to parse certain CSI escape sequences, and ends up echoing them.
This is unfortunate because it prevents programs like text editors and shells from using the kitty keyboard protocol

This was originally reported in the fish-shell matrix channel
I have not had a chance to reproduce this but it should be easy to do so.

Steps to reproduce the behavior.

printf '\x1b[=5u

This supposedly echoes 5u

What is the expected behavior?

Nothing should be echoed, since the string is a CSI-prefixed escape sequence

System information

not sure