Thanks for the patch. I'll consider this for a future bash version.

I don't think this approach is the right one. Since `exec' replaces the shell with the given program, this patch captures very few use cases.

If someone wants this behavior, won't they want it all the time? Isn't a better approach to make this dependent on a shell option?

This is a second attempt at the issue from https://savannah.gnu.org/patch/index.php?10445

Adds exec -f flag to avoid interpreting command as shell script on exec
failure.

POSIX standard specifies that, if exec system call fails ”due to an
error equivalent to the [ENOEXEC] error, the shell shall execute a
command equivalent to having a shell invoked with the command name as
its first operand”. The flag allows to avoid this behavior, making exec
builtin equivalent to the system call.

In addition to that, the second patch in the series includes a minor fix
for a potential out-of-bounds string access—though it’s likely not
reachable in practice.