It would be very useful to be able to search across multiple lines in "Find in Files". This doesn't work using patterns (\n) or by pasting in the line break character.
I realize this is all because `grep` doesn't really support multi-line searches, and it would not be difficult to implement this request.
It might be possible to add support for `pcregrep` to do what we need, with Geany complaining if you are searching for a linebreak-containing string and there being no `pcregrep` installed.
Or, we could dump grep and move find in files internally, using the same engine as the current Find feature.