Done. See
https://github.com/magthe/hsini/issues/16 for the issue about duplicate names, including a sample ini file. I've also opened
https://github.com/magthe/hsini/issues/17 about spaces in option names. I didn't try section names, but I've seen them with spaces in them as well, where they were used for creating GUI elements.
The wiki entry does mention the use of duplicate names for creating multi-valued options. It also mentioned duplicate section names, but not the specific use I'm dealing with.
I suspect fixing this in any of the current packages would require a fundamental rewrite of the packages I've looked at, as they all store options as Maps to string values, and sections as Maps to option value maps. They either need to store lists instead of maps, or use maps to polymorphic values.
For the record, I also created an issue for the in package
https://github.com/chrisdone/ini/issues/6, as it just hands back an empty config structure for the example file. Values outside of sections aren't handled.