Bottom portion of tab bar is still visible when in fullscreen mode

[ntwk]

I have recently moved to a new installation of Firefox and I have lost all of my about:config entries.

My preference is to hide as much of the Firefox user interface as possible and placing the following two options in my .pentadactylrc file seem to get me most of the way there:

set guioptions=''
set showtabline=never

However, I am finding that when in fullscreen mode, the bottom row of pixels of tab bar sometimes remains visible. It isn't initially visible when switching to fullscreen, but as I begin to navigate to other pages, it inevitably shows up.

I don't recall this being an issue in the past. This only seemed to present itself around the time I reinstalled Firefox and lost my previous about:config settings. I suspect there may have been an entry in my old about:config that prevented this issue.

Running :version gives the following:

Pentadactyl 7296 (created 2016/09/21 22:46:58) running on:
Mozilla/5.0 (X11; Linux x86_64; rv:49.0) Gecko/20100101 Firefox/49.0

Has anyone encountered such behavior and found fix?

[ntwk]

I just found the answer to my own question. The solution is to set browser.fullscreen.autohide to false in about:config.