Limiting search to a space that contains whitespace in its name doesn't work as expected

Suppose we have a space called "The Main Space", and in the Lucene search interface the user selects just that space as the target space. Instead of properly filtering results in that space, the composed query actually searches in the space "The", and also includes "Main" and "Space" as keywords to look. And since "The" is a stopword, the space filter will actually be completely ignored.