On Tue, Aug 3, 2021 at 1:44 PM Marcel Fabian Krüger <tex@2krueger.de> wrote:

Oops, looking back I realized that I remembered it incorrectly: The issue
was that the file couldn't get applied because the *patch* had Windows
lineendings. Not sure how that happened but anyway I stand corrected.

Indeed, that was the case.

I added the full file variation.c as an attachment. It belongs at

and again your variation.c attached has Windows line endings.
Anyway, variation.c from variation.c.patch is ok, it is  the same  of luaharfbuzz-master .

In general Windows line endings  are not a problem for me, because I am used  to run dos2unix  before.
The default diff (i.e. without ignoring blanks)  is annoying because it says  that all the lines differ, 
and I don't run diff -b  because spaces matter in comments .

Committed revision 7447.