[tex4ht] Bold index entries

["Jürgen Hubert"]

I've been using the tex4ht package for a while and I like it, but there's one minor issue when it comes to building a hyperlinked index that I haven't been able to solve.

I am using the following for my index setup:


\ifdefined\HCode
\usepackage[xindy,noautomatic]{imakeidx}
\else
\usepackage[]{imakeidx}
\fi
\usepackage{multibib}
\usepackage{tex4ebook}
\usepackage{xcolor}
\usepackage[hyperindex=true]{hyperref}


I am creating an ebook with a rather large index, and I want to make some index references bold to emphasize that this index. Thus, I am using

\index[topic]{dragon|textbf}

instead of

\index[topic]{dragon}

within the text. This works just fine when I use pdflatex. However, when I combine the ebook with the usual

tex4ebook -lm index -c myconfig.cfg -e mybuild.mk4 Sunken_Castles_Evil_Poodles.tex

command, I get the following error:

! Undefined control sequence.
l. 114	\item dragon, \hyperindexformat {\textbf}{15}, \hyperpage{15}

Now, as far as I can tell, if I just press <return> on each instance the ebook still has a hyperlinked index with bold entries at the right places - but it is annoying to have to do this each and every time I compile. Does anyone know a way around this?

Best regards,

- Jürgen Hubert