mysterious behaviour with fonts

[buhtz]

On the screenshot you see two terminal windows in the background. The
left is terminator the right is "Konsole" (KDE 4). Both of them use the
font "Hack" in 10pts.

But you can see they don't display the "vertical line" character the
same way. Terminator has a little space between them. But the python3
code producing this is exactly the same.

What is behind that behaviour?

[Stephen Boddy (stephen-j-boddy)]

Hmmmmmmmmmm.... OK, so I don't think this is a Terminator bug, though there is a way to "fix" it. I'll try and explain why.

Terminator is a Python program wrapped around the C based libvte terminal widget that is used by many, many terminal emulators, though not Konsole. Konsole uses completely different technologies.
Libvte is built on/for gtk libraries.
Gtk libraries use the libpango font renderer.

The default Terminator (and libvte) is based on gtk2 libraries. Another terminal app Guake is also gtk2 and also displays the strangeness in the vertical bars.

It is not clear if this strangeness is happening within the libvte widget, or the libpango font renderering, but it'll be one of those two.

Gnome Terminal is based on gtk3, which in turn has updated libvte and libpango, and it *doesn't* display this strangeness. So the problem is the old base libraries of default Terminator.

We do have an essentially complete, stable port to gtk3 which "fixes" the issue. It is typically a little more involved to get and install though. See this page if you want to give it a try:
http://gnometerminator.blogspot.de/2015/09/so-you-want-to-try-terminator-gtk3.html

I'll mark this as Fix Committed (just not released.)

[Egmont Koblinger (egmont-gmail)]

Note: gtk3 based vte "fixes" this issue by manually drawing these glyphs (U+2500 .. U+209F) instead of taking them from the font.

[Egmont Koblinger (egmont-gmail)]

... and the same goes for konsole, too.