Word stemming breaks the query string

I'm working with a site that has a content index with a few thousand nodes in it. While poking around with the index configuration I realized that stemming had not been enabled, so I turned it on and updated the index. The next day I was informed that the search system was no longer returning data as expected, and when I used Solr Devel to examine the query being sent to the server I discovered that the way it processes the keywords has changed. Before the change when I would search for "path/article" it would convert the string into "path article", but after enabling stemming it get turned into "patharticle".

So the question is, why does the stemmer processor do this? The problem appears to stem (cough) from the following line in processor_stemmer.inc:

    $value = implode('', $stemmed);

Shouldn't it instead be the following:

    $value = implode(' ', $stemmed);