I’ve tried to run the build with file.encoding=ISO-8859-1
As I said you need to set the metadataCharset on the zip task. Perhaps try UTF-8 and CP-1252
How can I know which charset winzip and 7zip assume?
I’m not sure, since it’s missing from the zip spec I guess all zip applications make their own choice, you’ll have to look at the winzip/7zip docs. If I was to take an educated guess I’d say Linux zipping tools use UTF-8 and Windows zipping tools use CP-1252
This issue should be ringing alarm bells in your head. The safest solution is to avoid special chars in filenames. Why would you want to produce a zip that can only be unzipped by certain tools?