Increase READ_BUF_SIZE, used in #'insert-file-contents-internal, to #x10000 src/ChangeLog addition: 2014-01-16 Aidan Kehoe <kehoea@parhasard.net> * fileio.c (READ_BUF_SIZE): Stack sizes > 2**16 elicited bugs back in August 1996, but there's nothing to indicate this is still the case. GNU uses a block size of #x10000, and that size works better with the coding system buffering, improving performance there; move to this value.