Ampersands in subject headings make for bad links

The subject heading links in the OPAC (under "Search for related items by subject") are meant to create a subject search that will retrieve records with the given subject heading. This does not work as expected, however, if the subject heading contains an ampersand. For example, the link for the subject heading "HISTORY -- United States -- State & Local -- New England (CT, MA, ME, NH, RI, VT)" points to url like:

https://DOMAIN/eg/opac/results?qtype=subject;locg=1;detail_record_view=0;_adv=1;badges=2%2C1;query=HISTORY%20--%20United%20States%20--%20State%20%26amp%3B%20Local%20--%20New%20England%20%28CT%2C%20MA%2C%20ME%2C%20NH%2C%20RI%2C%20VT%29

This results in a search for:

subject:HISTORY -- United States -- State & Local -- New England (CT, MA, ME, NH, RI, VT)

which will give no results.

Replacing "&" with an ampersand in the search box will return results.

I'm not sure if there are other special characters that may also be treated incorrectly.