Tab completion results in "unexpected EOF" error and crash

[Xu Lu]

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 
-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 yoga-luxu 5.11.6-arch1-1 #1 SMP PREEMPT Thu, 11 Mar 2021 
13:48:23 +0000 x86_64 GNU/Linux
Machine Type: x86_64-pc-linux-gnu

Bash Version: 5.1
Patch Level: 4
Release Status: release

Description:
        I was typing a command and want to use <Tab> to complete a program name 
after the following code:
                tig -C "$(dirname "$(base
        but bash shows me a "bash: unexpected EOF while looking for matching 
`)'" error.
        At first I found a similar issue in bash-completion here: 
https://github.com/scop/bash-completion/issues/189. But as I commented in that 
issue report, I can reproduce this bug even in vanilla bash. So I am now 
reporting this bug to bash.

Repeat-By:
        0. I tried to use the vanilla bash with steps 1-3, they can be skipped
        1. Removed `bash-completion` package
        2. Moved away my .inputrc for `readline`
        3. Start bash with
                $ bash --noprofile --norc
        4. Type (The first $ sign is shell prompt):
                $ "$(dirname "$(base
        5. Press <Tab> key
        6. The following message appears:
                bash: unexpected EOF while looking for matching `)'
        7. Type again:
                $ "$(dirname "$(base
        8. Press <Tab> key again
        9. The following message appears, and shell quits:
                free(): double free detected in tcache 2
                Aborted (core dumped)