If currently_executing_command was a subshell, it can end up freed by
the time executing_line_number checks it.
$ bash-asan -c '${ (:); }/'
=
ERROR: AddressSanitizer: heap-use-after-free on address 0x000106208a40
at pc 0x000102c8bf38
Hi.
Currently, Bash's manual definitions section mentions POSIX, but doesn't
explain what that abbreviature stands for («portable operating system
interface X», or something like that).
I think that abbreviatures can be confusing, especially when you don't get
to know what they stand for.
Theref
