Searching in index

[jdujava]

It would be awesome to have search functionality similar to / available in the index.

By accident I sometimes make a "doubleclick" <Mouse3> in the index, after which typing seems to trigger some kind of "search" functionality. Seems kinda strange, since it isn't documented, coudn't find any further information, and also works only if the given index entry starts with the given search prompt.

Seems to me like a useful thing to have, maybe even some kind of fuzzy matching would be sometimes desirable.