ConfluenceSpaceResolver#getSpaceByKey("FAQ") incorrectly returns the FAQ application's space

We have a fallback that returns the reference xwiki:SPACE for any requested SPACE in ConfluenceSpaceResolver#getSpaceByKey(String) if no resolver found any space and the xwiki:SPACE.WebHome exists.

This is to handle Confluence imports where the "Store Confluence Metadata" parameter is disabled. (and thus ConfluencePageClass objects are missing).

This is an optimistic guess but it is arguably incorrect to return the space of (well-known) apps. Maybe we should have a hardcoded list of spaces which we don't return because we know that they are not Confluence spaces.

At the same time, maybe the user didn't install the FAQ application and did migrate a Confluence space named FAQ so this is a tough problem to solve.

At some point we may need to drop the fallback, at the risk of breaking users.