Re: gnus: pgg-gpg-lookup-key uses wrong regular expression

[Simon Josefsson <jas@extundo.com>]

Manoj Srivastava <srivasta@debian.org> writes:

> Gnus v5.10.2
> GNU Emacs 21.3.1 (i386-pc-linux-gnu, X toolkit)
>  of 2003-10-31 on raven, modified by Debian
>
> Hi,
>
>       [Please retain the CC to 220521-forwarded@bugs.debian.org, so
>       that the Debian BTS has a record of your contribution]
>
> 	This was reported by a Debian user.
>
> In pgg-gpg-kookup-key (line 113 of pgg-gpg.el), that re-search-forward
> call places point at the end of "^\\(sec\\|pub\\):" Next, it splits
> that string at point on ":" separation. The problem is that if the
> string looks like this:
>
> "sec::foo:bar", split string returns '("foo" "bar"), not what the code
> actually expects it to return, '("" "foo" "bar"). The code wants to
> extract the third element of that list return from the split which is
> now unpredictable. This bug was provoked because when I'm signing, it
> parses a string like the one given, but when I'm verifying, it parses
> a string like "pub:u:foo:bar" which returns '("u" "foo" "bar") and the
> third element of that list is indeed what we want.
>
> From the documentation of the split-string function, "If there is
> match for SEPARATORS at the beginning of STRING, we do not include a
> null substring for that.  Likewise, if there is a match at the end of
> STRING, we don't include a null substring for that.
>
> Changing the regular expression to not include the first colon, so
> "^\\(sec\\|pub\\)" produces the proper result every time. Another
> option may be to search forward to the point found by the original
> regular expression and back up one place, so we know every time that
> the string to be split will begin with a separator.

The `split-string in Emacs CVS subr.el contain the following change
that fixes the problem.  As this changes the behaviour of
`split-string', there should be a NEWS entry about it, which there
isn't.  Trying the various examples in the Elisp manual also doesn't
return the same values.  I'll forward this to emacs-devel@gnu.org,
then we can find out whether the right solution is to fix Debian's
Emacs or fix Emacs CVS and Gnus.

	* subr.el (split-string): Implement specification that splitting on
	explicit separators retains null fields.  Add new argument
	OMIT-NULLS.  Special-case (split-string "a string").