* src/gpgme.h.in (GPGME_EXPORT_MODE_SECRET_SUBKEY): New.
* src/export.c (check_mode): Allow new mode and check for invalid
combinations.
(export_keys_start): Return error if new mode flag is set.
* src/engine-gpg.c (export_common): Implement.
* src/gpgme-tool.c (cmd_export): New option --secret-subkey.
* tests/run-export.c (main): New option --secret-subkey.
--
This adds support for exporting secret subkeys (via gpg's
--export-secret-subkeys) to gpgme_op_export[_ext][_start].
The flag is not supported by gpgme_op_export_keys[_start] because
there is no way to specify which subkey(s) to export with these
functions.
GnuPG-bug-id: 5757
0e19c48791