Requests the passphrase with a popup.
As from GPGME 1.15.0, the loopback pinentry is functional when exporting secret keys. It works fine when the exact passphrase is provided. If it's a wrong passphrase, GPGME does not generate an ::Error, but the app crashes with 'free(): double free detected in tcache 2'.
Hence, this patch cannot be committed to master.
Status : dangerous
Result : works and works not
Reason : a wrong passphrase means a crash
It may be of interest to copy WTreeTableNode items text content. These
cannot be selected with the mouse for copy to clipboard. The text is
here shown read-only in an extended auto-replaced WLineEdit.
In-place editing with a popup if user is allowed in app config file.
User must of course manage at least a private key. User identities of
target key may be selectively chosen. Optionally, certification may be
exportable and non-revocable.