boolean search not working as expected

[Natkeeran]

keyword = sri lanka

• (AND)
  subject = geography

Expected search result: None

However, it is showing results, even though non of the items in the result set do not have geography as subject.

https://tamil.digital.utsc.utoronto.ca/search-results?a%5B0%5D%5Bf%5D=all&a%5B0%5D%5Bi%5D=IS&a%5B0%5D%5Bv%5D=sri%20lanka&a%5B1%5D%5Bc%5D=AND&a%5B1%5D%5Bf%5D=subject&a%5B1%5D%5Bi%5D=IS&a%5B1%5D%5Bv%5D=geography

[kylehuynh205]

Fixed with #4

https://tamil.digital.utsc.utoronto.ca/search-results?a%5B0%5D%5Bf%5D=all&a%5B0%5D%5Bi%5D=IS&a%5B0%5D%5Bv%5D=%20sri%20lanka&a%5B1%5D%5Bc%5D=AND&a%5B1%5D%5Bf%5D=subject&a%5B1%5D%5Bi%5D=IS&a%5B1%5D%5Bv%5D=geography

[kylehuynh205]

PR to upstream is made.