Parameter expansion with extended pattern make system hang

[Hyunho Cho]

Machine: x86_64
OS: linux-gnu
Compiler: gcc
Compilation CFLAGS: -g -O2 -flto=auto -ffat-lto-objects -flto=auto
-ffat-lto-objects -fstack-protector-strong -Wformat
-Werror=format-security -Wall
uname output: Linux EliteBook 5.15.0-43-generic #46-Ubuntu SMP Tue Jul
12 10:30:17 UTC 2022 x86_64 x86_64 x86_64 GNU/Linux
Machine Type: x86_64-pc-linux-gnu

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

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#### "gcc --help" is already a short string, but the system hangs.
( without using extended pattern, there is no such problem )

bash$ help=$( gcc --help )

bash$ echo "${help//+([$' \t\n'])/ }"


#### It barely works for very short strings only. (so almost can not use)

bash$ help=$( gcc --help | sed -n '1, 10p' )

bash$ echo "${help//+([$' \t\n'])/ }"
Usage: gcc [options] file... Options: -pass-exit-codes Exit with highest
error code from a phase. --help Display this information. --target-help
Display target specific command line options.
--help={common|optimizers|params|target|warnings|[^]{joined|separate|undocumented}}[,...].
Display specific types of command line options. (Use '-v --help' to
display command
line options of sub-processes). --version Display compiler version information.
-dumpspecs Display all of the built in spec strings.