Tilde (~) in bash(1) is typeset incorrectly as Unicode character

[Thomas ten Cate]

Configuration Information [Automatically generated, do not change]:
Machine: x86_64
OS: linux-gnu
Compiler: gcc
Compilation CFLAGS: -march=x86-64 -mtune=generic -O2 -pipe -fno-plt
-fexceptions         -Wp,-D_FORTIFY_SOURCE=2 -Wformat
-Werror=format-security         -fstack-clash-protection
-fcf-protection -g
-ffile-prefix-map=/build/bash/src=/usr/src/debug/bash -flto=auto
-DDEFAULT_PATH_VALUE='/usr/local/sbin:/usr/local/bin:/usr/bin'
-DSTANDARD_UTILS_PATH='/usr/bin' -DSYS_BASHRC='/etc/bash.bashrc'
-DSYS_BASH_LOGOUT='/etc/bash.bash_logout'
-DNON_INTERACTIVE_LOGIN_SHELLS
uname output: Linux craig 6.4.4-arch1-1 #1 SMP PREEMPT_DYNAMIC Wed, 19
Jul 2023 19:19:38 +0000 x86_64 GNU/Linux
Machine Type: x86_64-pc-linux-gnu

Bash Version: 5.1
Patch Level: 16
Release Status: release

Description:

In the bash manual page (`man bash`), the ASCII tilde character '~'
(0x7e) is replaced by the Unicode character '˜' (U+02DC SMALL TILDE):

    $ man bash | grep 'additional binary operator'
                  An additional binary operator, =˜, is available,
with the same prece‐

The same happens for the use of ~ as a shorthand for the home
directory. This makes the manual page incorrect, and difficult to
search.

It looks like there is an ASCII tilde character in the man page's source code:

    $ gunzip -c /usr/share/man/man1/bash.1.gz | grep 'additional
binary operator'
    An additional binary operator, \fB=~\fP, is available, with the same

I don't know the first thing about groff, but `man groff_char`
suggests that ~ is indeed rendered as "modifier tilde", and that one
should write \(ti to obtain an actual tilde character.

I'm guessing the manpage is generated from texinfo, so if this is
actually a bug in texinfo, feel free to forward this email to
bug-texinfo at gnu.org.