Στις Τρί 17 Οκτ 2023 στις 12:20 μ.μ., ο/η Ulrike Fischer <lua...@nililand.de> έγραψε:
> Am Tue, 17 Oct 2023 09:51:55 +0300 schrieb Nikos Platis: > > > Dear all, > > > > I came across a rather strange issue while using lualatex with > babel-greek. > > I am posting here because I believe it is mostly related to lua(la)tex > and > > less to babel-greek. > > > > Here is an MWE: > > > > ---------------------------- > > % !TeX program = lualatex > > > > \documentclass{book} > > > > \usepackage[sf,bf]{titlesec} > > > > \usepackage[greek]{babel} > > \babelfont[greek]{rm}{Times New Roman} > > \babelfont[greek]{sf}{Arial} > > > > % \usepackage{polyglossia} > > % \setmainlanguage{greek} > > % \newfontfamily\greekfont[Script=Greek]{Times New Roman} > > % \newfontfamily\greekfontsf[Script=Greek]{Arial} > > > > % \usepackage[no-math]{fontspec} > > % \defaultfontfeatures{Ligatures=TeX} > > % \setmainfont{Times New Roman} > > % \setsansfont{Arial} > > % \usepackage{xgreek} > > > > \begin{document} > > > > \tableofcontents > > > > \chapter{Πρώτο Κεφάλαιο} > > Καλησπέρα \TeX. Πρώτο Κεφάλαιο. > > > > \end{document} > > ---------------------------- > > > > I was compiling this on fully updated Arch Linux with lualatex from > texlive > > (not Arch Linux packages). The result is the attached pdf file. You can > see > > the strange accents in "Περιεχόμενα" and "Κεφάλαιο". You can also see > that, > > for example, "Κεφάλαιο" appears correctly in the text. > > > > After a lot of testing, I found out that this happens only for lualatex > > (not xelatex) with babel-greek (not polyglossia or xgreek) (only in the > > "stock" strings, "Περιεχόμενα", "Κεφάλαιο") and lualatex from texlive > (not > > with lualatex from the Arch Linux package). > > > > [....] > > The crucial difference is probably in harfbuzz. But how can this impact > the > > output in the ways described above? > > The harfbuzz version is not relevant. > > In the faulty words the ά is not U+03AC (alpha with tonos) but U+3B1 > (alpha) with a following U+0301 (combining acute accent) (and > similar for the other char with accent). > > If the greek hyphenation patterns are used an discretionary is > inserted between char and accent and that disturbs the placement: > > \documentclass{book} > > \usepackage{babel} > \usepackage{fontspec} > \setmainfont{Times New Roman} > \setsansfont{Arial} > \textwidth=1pt > \begin{document} > \selectlanguage{greek} > \showoutput > > Κεφάλαιο > Κεφάλαιο > > \sffamily > Κεφάλαιο > Κεφάλαιο > > \end{document} > > basically it means that the greek hyphenation patterns needs a > correction, see https://tex.stackexchange.com/a/340164/2388 and > https://tex.stackexchange.com/q/330180/2388 for a similar problem > with russian. > > You can avoid the problem by using the harfbuzz renderer, e.g. > \babelfont[greek]{sf}[Renderer=harfbuzz]{Arial} > It typically suppress some problematic hyphenation points as it > builds clusters earlier. (polyglossia uses harfbuzz by default, > that's why you don't see the problem there). > > Another option is to redefine \contentsname and \chaptername and to > remove the accent introduced by babel-greek here: > > \addto\captionsgreek{\renewcommand\chaptername{Κεφάλαιο}% > \renewcommand\contentsname{Περιεχόμενα}} > > > The real fix is naturally to correct the hyphenation patterns. > > > > -- > Ulrike Fischer > http://www.troubleshooting-tex.de/ > > Thank you for your prompt answer. I remember that in the past I had witnessed similar problems when copying texts from a Mac which, I think, uses combining accents. I will write to the tex-hyphen list about it. It is still puzzling, though, why the problem was not present earlier (around June, for example, I was working with the same document that triggered this report, without any issues) or it does not show using the Arch Linux lualatex (which is packaging a texlive version around March). Maybe something has changed with babel-greek in the meantime.