Bug#886576: nautilus: Nautilus "Decrypt" context menu not displayed/working [with Seahorse]

[Harrison]

Package: nautilus
Version: 3.22.3-1+deb9u1
Severity: normal

I believe the bug is in Nautilus but does involve GnuPG "secret keys" in
Seahorse. I "imported" an existing "secret key" using a "gpg --import
private.key", set trust to "ultimate" and verified that I could encrypt/decrypt
using the "gpg" CLI.

The Nautilus "Encrypt" context menu is displayed and functions correctly.
However, the "Decrypt" context menu is not displayed UNLESS I invoke it with
"sudo nautilus"?  But, the "Decrypt" fails with a message that I "probably
don't have the secret key"?



-- System Information:
Debian Release: 9.3
  APT prefers stable-updates
  APT policy: (500, 'stable-updates'), (500, 'stable')
Architecture: amd64 (x86_64)
Foreign Architectures: i386

Kernel: Linux 4.9.0-5-amd64 (SMP w/8 CPU cores)
Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8), LANGUAGE=en_US.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)

Versions of packages nautilus depends on:
ii  desktop-file-utils         0.23-1
ii  gsettings-desktop-schemas  3.22.0-1
ii  gvfs                       1.30.4-1
ii  libatk1.0-0                2.22.0-1
ii  libc6                      2.24-11+deb9u1
ii  libcairo-gobject2          1.14.8-1
ii  libcairo2                  1.14.8-1
ii  libexempi3                 2.4.1-1
ii  libexif12                  0.6.21-2+b2
ii  libgail-3-0                3.22.11-1
ii  libgdk-pixbuf2.0-0         2.36.5-2+deb9u1
ii  libglib2.0-0               2.50.3-2
ii  libglib2.0-data            2.50.3-2
ii  libgnome-autoar-0-0        0.1.1-4+b1
ii  libgnome-desktop-3-12      3.22.2-1
ii  libgtk-3-0                 3.22.11-1
ii  libnautilus-extension1a    3.22.3-1+deb9u1
ii  libpango-1.0-0             1.40.5-1
ii  libselinux1                2.6-3+b3
ii  libtracker-sparql-1.0-0    1.10.5-1
ii  libx11-6                   2:1.6.4-3
ii  nautilus-data              3.22.3-1+deb9u1
ii  shared-mime-info           1.8-1

Versions of packages nautilus recommends:
ii  gnome-sushi      3.21.91-2
ii  gvfs-backends    1.30.4-1
ii  librsvg2-common  2.40.16-1+b1

Versions of packages nautilus suggests:
ii  brasero              3.12.1-4
ii  eog                  3.20.5-1+b1
ii  evince [pdf-viewer]  3.22.1-3+deb9u1
ii  nautilus-sendto      3.8.4-2+b1
ii  totem                3.22.1-1
ii  tracker              1.10.5-1
ii  xdg-user-dirs        0.15-2+b1

-- no debconf information