Underscore not shown at some DejaVu mono fonts

[Martin Saturka]

Ubuntu 16.04.3 LTS, fonts-dejavu 2.35-1,
mono underscore character is shown as space, issue seen:

* first noticed at Tcl/Tk applications, see this https://core.tcl.tk/tk/tktview/6386ce66a48d530747763d5fa97d3c96f8584f73 (14pixel-sized mono font) and this https://core.tcl.tk/tk/tktview/d4e20ca3dc tickets there;

* then I've met this font bug at Geany: DejaVu Sans Mono: 14, 17, all styles, and alike for Bitstream Vera Sans Mono at 14/17 sizes; set editor fonts (in preferences/interface) to these fonts, underscore disappears.

Since it is both at a Gtk application (Geany) and Tcl/Tk applications, it should be a font issue. It seems that DejaVu Sans Mono have generally issues, thus setting some another font as the system default Mono font would be reasonable (Liberation Mono seems to work properly).
Notice that mono fonts are commonly used for programming, and underscores are common in code, thus it is quite a problem to have spaces instead of underscores in system default mono font.

[A.M.Danischewski (adam-danischewski)]

This is still a problem.

NAME="Ubuntu"
VERSION="19.10 (Eoan Ermine)"
ID=ubuntu
ID_LIKE=debian
PRETTY_NAME="Ubuntu 19.10"
VERSION_ID="19.10"

I haven't changed anything as far as I know yet suddenly Geany stopped displaying underbars. Font was Monospace (whatever that is fc-list doesn't show anything named that) all sizes.

Changing to font Droid Sans Mono for Powerline worked for me - also working: Free Mono, Fira Mono for Powerline, Go Mono for Powerline and Noto Mono.

[A.M.Danischewski (adam-danischewski)]

Oh, ya forgot to mention all the DejaVu Sans Mono fonts also don't display the underbar in Geany.

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Yurx Cherio (cherio-e)]

Same here on a brand new xubuntu 20.04.
I like the way text is condensed and the lines are sitting tight but missing underscores are a deal breaker.