Comment 30 for bug 873470

Two years ago, Alexander Larsson mentionned to me (in passing at Desktop Summit) an idea to solve this exact problem: his idea was to introduce the concept of private inheritance in s-m-i, so that one could say "opendocument files inherit privately from zip", i.e. the fact that it's zip is an implementation detail.

We could then have two ways to check if mimetype A inherits from mimetype B: including or excluding private inheritance.

When looking for an application that handles mimetype A (for launching the app), we would exclude it.

But when the application itself would check "is this file's mimetype supported by one of my plugins" then it would include it.

And when a filemanager wants to populate the "right click / open with ..." submenu, it could also include it, so that people could actually launch an archive program to inspect an opendocument file.

Same thing with application/octet-stream: the implied inheritance from all files could be private, so that associating an hex editor with that mimetype doesn't make it launch by default, but makes it available in the "open with..." submenus.