master updated (2d4058b3ff -> f3408af0a3)

[Jim Porter]

jporter pushed a change to branch master.

      from  2d4058b3ff Merge from origin/emacs-28
       new  30320d9420 Only set Eshell execution result metavariables when 
non-nil
       new  9d4fa4ed4b Allow using dollar expansions in Eshell conditionals
       new  f3408af0a3 Make '$?' and '$$' variables more consistent in Eshell


Summary of changes:
 doc/misc/eshell.texi              |  77 ++++++++---
 etc/NEWS                          |   7 +
 lisp/eshell/em-alias.el           |   2 +-
 lisp/eshell/esh-cmd.el            |  85 +++++++-----
 lisp/eshell/esh-io.el             |  50 ++++---
 lisp/eshell/esh-proc.el           |  68 +++++----
 test/lisp/eshell/esh-cmd-tests.el | 283 ++++++++++++++++++++++++++++++++++++++
 test/lisp/eshell/esh-var-tests.el |  56 +++++++-
 test/lisp/eshell/eshell-tests.el  |  53 -------
 9 files changed, 508 insertions(+), 173 deletions(-)
 create mode 100644 test/lisp/eshell/esh-cmd-tests.el