Interaction between clean/smudge and git status

Hi,

I have tried for the first time the .gitattributes filter option, setting a clean and a smudge filter for a certain type of files.

What makes me wonder is that using filters, after a clean checkout git status says that everything is changed.

My filter is a very short script that operates on zip files. The clean command re-zips them so that the content is merely stored. The smudge one re-zips them so that the content is deflated again.

This kind of filter helps very much the git repacking when zip files or openoffice files are around.

But unfortunately, with it git shows everything as changed, which is not that nice.

Is this the expected behaviour of the smudge filter? Unfortunately I have been able to find very little documentation on it (only a bit in the gitattributes man page), so maybe I am missing something.