As noted on the user list by Scott Hollenbeck the following warning can be logged by solr...
no default request handler is registered (either '/select' or 'standard')
...even if there is both a handler named "standard" and a handler (in his case named "pinkPony") defined as default="true".
The code in question appears to be total nonsense...
- PluginBag.alias is not documented, but appears to be a mutating operation that adds an alias if and only if the first arg is aname of something that exists, and the second arg is a name that does not already exist – returning true if the alias is added
- if an alias already exists with the (default) name "" (which initHandlersFromConfig takes care of registring before this code) then neither of these can be made the new default.
- just because neither of these aren't made the default here, doesn't mean there isn't already a default handler – it actually means the exact oposite
- if the goal was to log an error when there is no default, then that should have just been checked directly