Search in sphinx doesn't work for short searches

See most of bullet 2 here:
https://meetings.opendaylight.org/opendaylight-docs/2016/docs/opendaylight-docs-docs.2016-08-30-19.05.html

Quoted here:

Searching for "yang ide" fails to find anything:
http://docs.opendaylight.org/en/stable-boron/search.html?q=yang+ide&check_keywords=yes&area=default

Even though these exists:
http://docs.opendaylight.org/en/stable-boron/getting-started-guide/project-specific-guides/yangide.html
http://docs.opendaylight.org/en/stable-boron/user-guide/yang-ide-user-guide.html

Specifically that seems to be because searching for "ide" returns nothing:
http://docs.opendaylight.org/en/stable-boron/search.html?q=ide

This appears to be a bug in Sphinx, which should either support short searches or or at least throw an error explaining that there might be no results because of a limitation instead of there actually being no results.