Customizing index and using doc package

I needed an index for my master thesis and wanted to adjust the index with a style file. It took me 3 hours to get it working with the template I am using. My style file was always ignored until I've found out that the problem is caused by including the doc package.

Here is an example:

\documentclass{article} \usepackage{makeidx} % \usepackage{doc} % somehow changes the index, indexname etc. \makeindex \begin{document} \tableofcontents \index{bla} bla. \index{blub} blub. \addcontentsline{toc}{chapter}{Stichwortverzeichnis} \def\indexname{Stichwortverzeichnis} \makeatletter \printindex \makeatother \end{document} 

I've uploaded my index style file here, but I doubt that this is a problem with my index style file?!

To compile you'll need to do (assuming you will save the example to 'index.tex' and the index style file to 'gind.ist'):

latex index.tex makeindex -s gind.ist -g index # or another index style latex index.tex latex index.tex dvips index.dvi ps2pdf index.ps 

Here the result with the doc package (ingoring my index style file): And here the result without the doc package (using my index style file):

My question: Is this an explicit behaviour of the doc package or is it a nasty side-effect of the package? I've just read the short explanation of the package on CTAN but couldn't answer this question by myself.