We've seen in a couple of instances that it is possible for remote settings to return an empty configuration. Although these cases have been resolved, we already have code to manage errors and fallback to the built-in dump.

I'd therefore like to widen that code to include any exception, and also handle the case where the results are empty (which should never happen). This should provide us with a bit more protection in the event something does go wrong, as the search service is an important part of the browser, I think resilience is worth having.

The other case of returning an empty configuration isn't likely to be an issue, however, I think it is still worth hardening, and ensuring we do our best to get valid data, in case we hit something unexpected.

https://hg.mozilla.org/mozilla-central/rev/4a7a62797c25