GIF Thumbnails are broken (long fix inside)

[BaronKrause]

In the current Pop! OS (and both Ubuntu 18.10 and I believe 19.04's beta) GIF thumbnails are currently broken due to a combination of 2 separate issues: bubblewrap interfering with the thumbnailer, and the stock gdk-pixbuf-thumbnailer.thumbnailer not actually supporting gif thumbnails, even though it has gif listed in it.

The first problem can be worked around with a guide created by Nicolas Bernaerts http://www.bernaerts-nicolas.fr/linux/74-ubuntu/360-ubuntu-nautilus-external-thumbnailer-failure

the short of it is that it replaces:

--symlink usr/bin /bin --symlink usr/sbin /sbin

with:

--ro-bind /bin /bin --ro-bind /sbin /sbin

After you implement that fix you still need to address the issue with the stock thumbnailers gif support by making a custom one that uses imagemagick by creating a file called gif.thumbnailer inside /usr/share/thumbnailers and entering this inside:

[Thumbnailer Entry]
TryExec=convert
Exec=convert %i[0] -resize %sx%s %o
MimeType=image/gif;

After that you need to edit the stock gdk-pixbuf-thumbnailer.thumbnailer inside that same directory and delete the "image/gif;" entry or else it will override the thumbnailer you just made and continue not showing gif thumbnails like it always does.

After all this you get GIF thumbnails back. Just figured I would put this all here incase it isn't fixed in the most current version of Pop! OS coming out, and I haven't actually seen the workaround for gdk-pixbuf-thumbnailer.thumbnailer listed anywhere else.

[mmstick]

We'll likely fix this after the release of 19.04. Will verify if this also occurs there.

[mmstick]

Also, patches are welcome :package: