Emacs line no. in status bar set to '??'

Question

I am having an issue in emacs (24) where occasionally the line no. in the status bar gets set to ??, e.g.

U:---   filename   All   (1000, 4)    (Conf[Unix])

switches to:

U:---   filename   All   (??, 4)    (Conf[Unix])

its a bit irritating and something I'd like to be able to prevent

Answer 1

From the emacs documentation for line-number-mode:

"Line numbers do not appear for very large buffers and buffers with very long lines; see variables line-number-display-limit and line-number-display-limit-width."

If you set line-number-display-limit to nil, you should always see a line number.