https://bugzilla.redhat.com/show_bug.cgi?id=1437999
--- Comment #49 from Adam Goode adam@spicenitz.org --- I can reproduce the line spacing differences with ftdiff: ftdiff -s 8 -r 96 /usr/share/fonts/dejavu/DejaVuSansMono.ttf
So I don't think pango nor vte are doing anything odd. The font really does shift around a bit at this small size with these edge rounding cases. (And it does look better with the newer freetype to my eye.)
The only thing is to give gnome-terminal a spacing parameter so that folks can adjust this as desired. https://bugzilla.gnome.org/show_bug.cgi?id=738781
Not sure if you want to block this bug on any potential gnome-terminal/vte enhancements.
Thanks to everyone for all the thorough investigations.