Casefolding for Turkish

[rstub]

The case folding in the following document is not correct when using XeTeX or LuaTeX:

\documentclass{article}

\usepackage{babel}
\babelprovide[import=tr,main]{turkish}

\begin{document}

İ -- \MakeUppercase{i}

I -- \MakeUppercase{ı}

i -- \MakeLowercase{İ}

ı -- \MakeLowercase{I}

\end{document}

Result:

The correct result can be obtained from using polygloassia instead of babel, i.e.

\usepackage{polyglossia}
\setmainlanguage{turkish}

Result:

References:

• original TeX.SE question
• figures 5-14 and 5-15 in 5.18 Case Mappings

[jbezos]

I hope I can submit a new version later this month.

[jbezos]

Updated the ldf file and just submited to CTAN. Now I have to update the babel-*.ini/tex files.