[3.14] gh-138577: Mention Unix-specific limitations of `getpass.getpass(echo_char=...)` (GH-138677) by miss-islington · Pull Request #138696 · python/cpython

…s(echo_char=...)` (pythonGH-138677)

In bf8bbe9, `getpass.getpass` gained
the ability to provide keyboard feedback through `echo_char`.

On Unix, line editing shortcuts such as Ctrl+U were previously handled
as the terminal operates in canonical mode (see termios(3)). However,
since keyboard feedback requires to switch to noncanonical mode, this
now results in an inconsistency when `getpass.getpass` uses `echo_char`
as those shortcuts are no more supported. This limitation is specific
to Unix and does not affect Windows users where line editing shortcuts
were never supported.
(cherry picked from commit 074f3b2)

Co-authored-by: yagggi <fakepoet0101@gmail.com>