When I try the following
C-h f global-font-lock-mode-check-buffers
Press RET on the hyperlink font-core.el
I comes back at you with the following
verbatim text:
r-xrwS-w- 15810023/15240742 995161187 ;;; font-core.el --- Core interface to font-lock -*- lexical-binding: t; -*-
;; Copyright (C) 1992
And nothing else. This is clearly a bug in Emacs. Luckily for me I
can gunzip file font-core.el.gz and then save it as font-core.el for
browsing at my leisure.