\gdef\putwordAppendix{F\"uggel\'ek}
TeX complains when it generates the table of contents.
Numerous other txi-?? files do exactly that.
Please compare with them. There's no reason it would fail for you
and work for the rest. Be sure you are getting the right version of
texinfo.tex.
The other problem is, how to redefine @chapter , because @chapter calls
@parsearg which through \parsearg\chapteryyy calls \chapterzzz ...
Copying and modifying \chapter and the like is certainly the wrong way to go.
If all you want is a period after the chapter/section number, then the
right thing to do is add a simple macro in the appropriate spot which is
defined to nothing by default but txi-hu.tex can redefine to {.}.
In general, we must factor out whatever is needed, not redefine whole
huge complicated macros that change relatively frequently for unrelated
reasons.
Karl
