Consider the following code:
\documentclass{article}
\usepackage{fontspec}
\setmainfont[BoldItalicFont = {* Semibold Italic}]{Linux Libertine O}
\begin{document}
\textit{\textbf{V\char"0306}}
\end{document}
Why does this give the correct output with XeLaTeX, but not with LuaLaTeX?
XeLaTeX:

LuLaTeX:

(This question is a spin-off from Why choose LuaLaTeX over XeLaTeX?)

markandmkmkfeatures. Junicode has these features but fails the test. Amiri has themarkbut not themkmkfeature, and also fails this test. I haven’t found a font without these features which produces the desired output inluatex. – Thérèse Jun 13 '14 at 21:16mkmkshould not have any rule here since there are no mark to mark interaction involved. depending on how the font is built, you might not also need themarkfeature to get correct output. – خالد حسني Jun 16 '14 at 11:15closed as unclear what you're askingWhat? It's obvious! LuaTeX does it wrong while XeTeX is doing it correctly. What is the reason for that difference. There is no possibility how a question can be more clear that this one. – radlan Nov 02 '19 at 14:02