5.3: job error caused by funsub + bind + loadable builtin

[Koichi Murase]

Configuration Information [Automatically generated, do not change]:
Machine: x86_64
OS: linux-gnu
Compiler: gcc
Compilation CFLAGS: -march=native -O3
uname output: Linux chatoyancy 6.4.10-100.fc37.x86_64 #1 SMP
PREEMPT_DYNAMIC Fri Aug 11 15:18:39 UTC 2023 x86_64 x86_64 x86_64
GNU/Linux
Machine Type: x86_64-pc-linux-gnu

Bash Version: 5.3
Patch Level: 0
Release Status: devel

Description:

  DEBUG warnings are produced for inconsistent numbers of dead jobs
  when a function substitution is used with the loadable builtin
  `sleep' inside `bind -x'.  I guess this is related to the
  implementation of function substitutions newly introduced in 5.3,
  but I have not tried to pin down the problem in the codebase.

  Note: It does not seem to be reflected in the above auto-generated
  "Configuration Information", but I specified `--with-bash-malloc=no'
  as a ./configure option.

Repeat-By:

  $ PS1='\$ ' LANG=C bash-dev --norc
  $ enable -f /path/to/lib/bash/sleep sleep
  $ function f1 { for a in 1; do builtin sleep 0.1; done }
  $ builtin bind -x '"\C-t": v=${ f1 & }'
  $ <--- press <C-t> several times
  bash-dev: DEBUG warning: mark_dead_jobs_as_notified: ndead (0) !=
js.j_ndead (1)
  bash-dev: DEBUG warning: mark_dead_jobs_as_notified: ndead (0) !=
js.j_ndead (2)
  bash-dev: DEBUG warning: mark_dead_jobs_as_notified: ndead (0) !=
js.j_ndead (3)
  bash-dev: DEBUG warning: mark_dead_jobs_as_notified: ndead (0) !=
js.j_ndead (4)
  bash-dev: DEBUG warning: mark_dead_jobs_as_notified: ndead (0) !=
js.j_ndead (5)

  The value of `js.j_ndead' increases unlimitedly as typing C-t.

--
Koichi