Bug#620185: M-q problem in changelog mode

[David Bremner <bremner@debian.org>]

Peter Eisentraut <petere@debian.org> writes:

> """
> PACKAGE (VERSION) UNRELEASED; urgency=low
>
>   * foo
>   * bar bar bar bar bar bar bar bar bar bar bar bar bar bar bar bar bar bar bar
>   * baz
>
>  -- Peter Eisentraut <petere@debian.org>  Wed, 30 Mar 2011 23:05:11 +0300
> """
>
> If I move the cursor to the "bar" line and press M-q nothing happens.  If I
> insert a blank line between the "bar" and the "baz" lines, then M-q works on
> the "bar" line.  That seems wrong.

I guess this code hasn't changed much in the intervening years and the
bug still exists.

If I trace through filling the "bar" line, it fills from point 134 to
point 136 (the beginning of the next line), so it's pretty clear it's
not matching the entry properly.

I tried to debug this a bit, but I'm mystified by the regex used for
paragraph-start

Line 1363

 (set (make-local-variable 'paragraph-start) "\\*\\|\\s *$\\|\f\\|^\\<")

As far as I can understand, the second disjunct corresponds to the regex
'\s *', or any sequence of whitespace characters (including the empty
sequence).

This is equivalent to the '\s-*' it seems to have replaced.

I'd be surprised if emacs lisp regex syntax changed, so I guess this
made sense to someone at some point.