Apparently this has had two bugs since my last attempt to fix it (commit
0e7d960b998e7c6dc781dc37cb703cdb32232a5f).
* It had only one backslash before the `*', which does nothing; this
only worked because -- luckily -- Emacs treats a `*' not in
postfix-operator position literally.
* There was a stray `]' at the end of the `//' pattern, which caused
most attempts to match single-line comments to fail.
Oh, dear.
(defvar mdw-c-comment-fill-prefix
`((,(concat "\\([ \t]*/?\\)"
- "\\(\*\\|//]\\)"
+ "\\(\\*\\|//\\)"
"\\([ \t]*\\)"
"\\([A-Za-z]+:[ \t]*\\)?"
mdw-hanging-indents)