LGTM, thanks! And I think that `ssize_t` is a good type in general since it allows to use the value -1 as a special flag.
https://codereview.appspot.com/567090043/
Issue 5661: Fix some conversion warnings in Source_file. (issue 567090043 by nine.fierce.ballads@gmail.com)
lemzwerg--- via Discussions on LilyPond development Mon, 13 Jan 2020 09:57:46 -0800
