Duplicate of #2287, see that for workaround of faulty fonts.

Note: the times its visible in your example is when the colour scheme selects bold which the font clearly has right.

(Copied from https://github.com/geany/geany/issues/2466)

I just got the `line_height` workaround to work with excellent results. The `line_height` setting can be found in "Tools" > "Configuration Files" > "filetypes.common". To change this setting from its default `line_height=0;0;` there are two things to note:

* `#~` lines are commented and have no effect. * The file format is an [INI file](https://en.wikipedia.org/wiki/INI_file) so uncommenting the `line_height` line is insufficient because the `[styling]` section is also required; either uncomment this line or add a new `[styling]` section at the end.

The only uncommented lines in my filetypes.common are now:

``` [styling] line_height=0;2; ```

With this setting and DejaVu Sans Mono Book size 12, underscores are visible. Using `line_height=0;1;` also works, but `line_height=0;2;` gives me, for the first time ever, exact agreement (as far as I can tell) with the line height in xfce4-terminal.