I sent a patch to gcrypt-devel mailing list for the preparation of the change of RSA secret key checking.
If enabled, wrong RSA secret key (wrong means: under the Libre/OpenPGP specification) is rejected at import when gpg-agent calls gcry_pk_test_key.

I consider again about Ben's change. It could be simply support of the detection of the cancel situation where gpgme should return GPG_ERR_CANCELED (not related to single cancellation vs. whole cancellation).

I can't remember why Ben introduced the new status. OTOH, I wish that the Qt-Pinentry also emits a button_info line for closing the window. Normal users don't notice the difference but if you have a lot of private keys and you get a mail which has only hidden recipients the full_canceled is pretty useful. Also for other tasks like allow-mark-trusted: On Windows with the qt-pinentry I am always cursing about this but on my box I only need to close the pinentry window to get a fully_canceled

Alternative suggestion:

BTW, LibrePGP also demands p < q in "Algorithm-Specific Part for RSA Keys".

added vsd34 for the resetting of the defaults

I investigated the introduction of STATUS_CANCELED_BY_USER and GPGME_STATUS_CANCELED_BY_USER:
rG31e47dfad0f4: gpg: Add canceled status message.
rM35ca460019ea: Parse STATUS_CANCELED_BY_USER.

For OpenSSH, ssh-agent spec. defines p, q, and qInv.
FIPS has: FIPS 186-5 and SP 800-56Br2.

existing standards

Filter 16 is the new filter for valid certificates. The problem could be that the version you tested did not yet have this filter.

Windows button order seems to be described, there: https://web.archive.org/web/20161013015954/https://msdn.microsoft.com/en-us/library/dn742499.aspx . I could not find a more up-to-date official reference. Likely, this still applies, though. This specifies (left to right): OK/[Do it]/Yes, [Don't do it]/No, Cancel, Apply (if present), Help (if present)

branch work/tfry/seclevel_ui