bug#45257: 27.1; ido-find-file incorrectly handles directory names beginning with tilde(~)

[benthor]

Steps to reproduce:
mkdir -p /tmp/ido/~example/
emacs -Q
M-x ido-mode
C-x C-f //tmp/ido/~example/test

Expected behavior:
See "Find file: /tmp/ido/~example/test [No match]" in Minibuffer

Observed behavior:
See "~/~example/test [No match]" in Minibuffer


In GNU Emacs 27.1 (build 1, x86_64-pc-linux-gnu, GTK+ Version 
3.24.22, cairo version 1.17.3)
of 2020-08-28 built on juergen
Windowing system distributor 'The X.Org Foundation', version 
11.0.12010000
System Description: Arch Linux

Recent messages:
For information about GNU Emacs and the GNU system, type C-h C-a.
Ido mode enabled
Quit

Configured using:
'configure --prefix=/usr --sysconfdir=/etc --libexecdir=/usr/lib
--localstatedir=/var --with-x-toolkit=gtk3 --with-xft 
--with-wide-int
--with-modules --with-cairo --with-harfbuzz 'CFLAGS=-march=x86-64
-mtune=generic -O2 -pipe -fno-plt' CPPFLAGS=-D_FORTIFY_SOURCE=2
LDFLAGS=-Wl,-O1,--sort-common,--as-needed,-z,relro,-z,now'

Configured features:
XPM JPEG TIFF GIF PNG RSVG CAIRO SOUND GPM DBUS GSETTINGS GLIB 
NOTIFY
INOTIFY ACL GNUTLS LIBXML2 FREETYPE HARFBUZZ M17N_FLT LIBOTF ZLIB
TOOLKIT_SCROLL_BARS GTK3 X11 XDBE XIM MODULES THREADS LIBSYSTEMD 
JSON
PDUMPER LCMS2 GMP

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

Major mode: Fundamental

Minor modes in effect:
 tooltip-mode: t
 global-eldoc-mode: t
 electric-indent-mode: t
 mouse-wheel-mode: t
 tool-bar-mode: t
 menu-bar-mode: t
 file-name-shadow-mode: t
 global-font-lock-mode: t
 blink-cursor-mode: t
 auto-composition-mode: t
 auto-encryption-mode: t
 auto-compression-mode: t
 buffer-read-only: t
 line-number-mode: t
 transient-mark-mode: t

Load-path shadows:
None found.

Features:
(shadow sort mail-extr emacsbug message rmc puny dired 
dired-loaddefs
format-spec rfc822 mml easymenu mml-sec password-cache epa derived 
epg
epg-config gnus-util rmail rmail-loaddefs text-property-search 
time-date
subr-x mm-decode mm-bodies mm-encode mail-parse rfc2231 mailabbrev
gmm-utils mailheader cl-loaddefs cl-lib sendmail rfc2047 rfc2045
ietf-drums mm-util mail-prsvr mail-utils ido seq byte-opt gv 
bytecomp
byte-compile cconv tooltip eldoc electric uniquify ediff-hook 
vc-hooks
lisp-float-type mwheel term/x-win x-win term/common-win x-dnd 
tool-bar
dnd fontset image regexp-opt fringe tabulated-list replace 
newcomment
text-mode elisp-mode lisp-mode prog-mode register page tab-bar 
menu-bar
rfn-eshadow isearch timer select scroll-bar mouse jit-lock 
font-lock
syntax facemenu font-core term/tty-colors frame minibuffer 
cl-generic
cham georgian utf-8-lang misc-lang vietnamese tibetan thai 
tai-viet lao
korean japanese eucjp-ms cp51932 hebrew greek romanian slovak 
czech
european ethiopic indian cyrillic chinese composite charscript 
charprop
case-table epa-hook jka-cmpr-hook help simple abbrev obarray
cl-preloaded nadvice loaddefs button faces cus-face macroexp files
text-properties overlay sha1 md5 base64 format env code-pages mule
custom widget hashtable-print-readable backquote threads dbusbind
inotify lcms2 dynamic-setting system-font-setting 
font-render-setting
cairo move-toolbar gtk x-toolkit x multi-tty make-network-process 
emacs)

Memory information:
((conses 16 60102 15242)
(symbols 48 6307 1)
(strings 32 25460 1851)
(string-bytes 1 638168)
(vectors 16 10771)
(vector-slots 8 135937 13568)
(floats 8 27 19)
(intervals 56 191 0)
(buffers 1000 12))