Re: Infinite loop triggered by extglob +(!(x))y

[Greg Wooledge]

On Sun, Jul 25, 2021 at 07:09:50PM +0200, andrej--- via Bug reports for the GNU 
Bourne Again SHell wrote:
> Description:
>       An extglob like +(!(x))y causes Bash to freeze with a 100% CPU 
> utilization.
>       At the first glance the freeze doesn't seem to depend on the 
> (non-)existence of matching paths.

The files do seem to matter.

unicorn:~/tmp$ echo +(!(x))y
servers-to-try
unicorn:~/tmp$ cd /tmp
unicorn:/tmp$ echo +(!(x))y
^C^C^ZKilled

It's a really bad runaway, requiring SIGKILL from another terminal to
stop it.