Fix handling of output handles in nested Eshell forms

Previously, the output handles in nested forms would be reset to the
default, leading to wrong behavior for commands like

  {echo a; echo b} > file

"b" would be written to "file" as expected, but "a" would go to
standard output (bug#59545).

* lisp/eshell/esh-cmd.el (eshell-parse-command): Use
'eshell-with-copied-handles' for each statement within the whole
Eshell command.

* test/lisp/eshell/esh-io-tests.el (esh-io-test/redirect-subcommands)
(esh-io-test/redirect-subcommands/override)
(esh-io-test/redirect-subcommands/interpolated): New tests.

* test/lisp/eshell/em-script-tests.el
(em-script-test/source-script/redirect)
(em-script-test/source-script/redirect/dev-null): New tests.
(em-script-test/source-script, em-script-test/source-script/arg-vars)
(em-script-test/source-script/all-args-var): Tweak names/docstrings.

* test/lisp/eshell/em-extpipe-tests.el (em-extpipe-tests--deftest):
Skip over the newly-added 'eshell-with-copied-handles' form when
checking the parse results.

* test/lisp/eshell/em-tramp-tests.el (em-tramp-test/su-default)
(em-tramp-test/su-user, em-tramp-test/su-login)
(em-tramp-test/sudo-shell, em-tramp-test/sudo-user-shell)
(em-tramp-test/doas-shell, em-tramp-test/doas-user-shell): Update
expected command forms.

0 files changed, 0 insertions, 0 deletions