Uncaught exception when the default environment does not exist (patch)

apachesolr_get_solr() throws exceptions when the default environment stored in the apachesolr_default_environment is not a valid environment; this can happen if the default environment is deleted programmatically or if the variable is unset and is allowed to default to 'solr' when the default 'solr' environment has been deleted.

A site is probably doing something wrong if this variable is not present and set to a valid environment, but it can potentially happen with Features and exportable environments. I get the impression that this function is supposed to throw an exception, and that callers are expected to wrap it in a try-catch, but there are several functions that do not do this. Should all uses of apachesolr_get_solr() be wrapped in try-catch blocks? If so, I'd be happy to write a patch...