Port trust fixes#12929

Merged

joyceerhl merged 3 commits intorelease-2020.07from

port-trust-fixes

Jul 13, 2020

Commits on Jul 13, 2020

Fix regressions in trusted notebooks (#12902)
joyceerhl
committed
Recover from ENOENT due to missing parent directory when trusting notebook (#12913)
joyceerhl
committed
Disable keydown on native cells in untrusted notebooks (#12914)
joyceerhl
committed