* src/gpgme.h.in (GPGME_ENCRYPT_ARCHIVE): New encryption flag.
* src/engine-gpg.c (arg_and_data_s): New field gpg_arg.
(engine_gpg): New flag use_gpgtar.
(_add_arg): Add argument gpg_arg and set it.
(add_arg_ext, add_arg_with_locp, add_arg, add_arg_pfx, add_arg_len):
Adjust call of _add_arg.
(add_arg_with_locp): Add argument front.
(add_gpg_arg, add_gpg_arg_with_value): New.
(gpg_new): Use add_gpg_arg_with_value for gpg-only options with a value
and add_gpg_arg for gpg-only options without.
(build_argv): Consider usage of gpgtar when counting arguments to pass
to gpg/gpgtar. Prepend "--gpg-args" to all gpg-only arguments if gpgtar
is used.
(start): Set program to use. Read diagnostics output from stderr when
using gpgtar. Do not pass --status-fd to gpgtar for gpg < 2.4.1. Use
add_gpg_arg_with_value for --lc-ctype and --lc-messages.
(gpg_encrypt): Set use_gpgtar engine flag if GPGME_ENCRYPT_ARCHIVE flag
is set. Check for new enough gpg and incompatible flags. Use
add_gpg_arg_with_value for gpg-only options with a value and
add_gpg_arg for gpg-only options without a value. Set extra options
for gpgtar and pass input data to stdin when using gpgtar.
* src/engine-gpgsm.c (gpgsm_encrypt): Return error if new flag is set.
* src/engine-uiserver.c (uiserver_encrypt): Ditto.
* tests/run-encrypt.c (show_usage): New options --archive and
--diagnostics.
(main): Parse new options. Encrypt with gpgtar if --archive is given.
Print stderr of gpg/gpgtar if --diagnostics is given.