bug#51666: 28.0.60; comint-password-prompt-regexp too restrictive (again)

[Stephen Berman]

On one of my systems, when using ssh in shell-mode (M-x shell), the
password prompt does not appear in the minibuffer but only in the
*shell* buffer directly under the ssh invocation, and the password is
not hidden when it's entered.  The password prompt has this form:

(user@host) Password:

and comint-password-prompt-regexp fails to match it.  By contrast,
eshell-password-prompt-regexp does match this prompt.  This is with
openssh-8.6p1.  The fix in bug#43003 doesn't help here.


In GNU Emacs 28.0.60 (build 4, x86_64-pc-linux-gnu, GTK+ Version 3.24.29, cairo 
version 1.17.4)
 of 2021-11-06 built on strobelfs
Repository revision: 0d6b2b0b9dcb958193f21bd5bd3bd389a42b3de2
Repository branch: emacs-28
Windowing system distributor 'The X.Org Foundation', version 11.0.12011000
System Description: Linux From Scratch 10.2-rc1

Configured using:
 'configure --with-native-compilation 'CFLAGS=-Og -g3'
 PKG_CONFIG_PATH=/opt/qt5/lib/pkgconfig'

Configured features:
ACL CAIRO DBUS FREETYPE GIF GLIB GMP GNUTLS GSETTINGS HARFBUZZ JPEG JSON
LCMS2 LIBSYSTEMD LIBXML2 MODULES NATIVE_COMP NOTIFY INOTIFY PDUMPER PNG
RSVG SECCOMP SOUND THREADS TIFF TOOLKIT_SCROLL_BARS X11 XDBE XIM XPM
GTK3 ZLIB

Important settings:
  value of $LANG: en_US.UTF-8
  locale-coding-system: utf-8-unix