comment-valid-prefix-p

comment-valid-prefix-p is a compiled Lisp function in `newcomment.el'.

(comment-valid-prefix-p PREFIX COMPOS)

Check that the adaptive fill prefix is consistent with the context.
PREFIX is the prefix (presumably guessed by `adaptive-fill-mode').
COMPOS is the position of the beginning of the comment we're in, or nil
if we're not inside a comment.