The Gnus registry extracts some header values from messages using
`gnus-registry-fetch-header-fast'. There are two problems with this:

1. It is called with its arguments reversed which (by luck) causes it to
always return nil.

2. If it were called correctly it would raise an error, as it tries to
use `assq' to find a string key in a vector. Maybe `gnus-data-header'
used to return a different value, but so far as I can tell this hasn't
worked for quite some time.

It's a bug, but it's one that hasn't done much harm for a while, so I'm
proposing this for master.

Eric


In GNU Emacs 27.0.50 (build 1, x86_64-pc-linux-gnu, GTK+ Version 3.22.26)
 of 2017-12-16 built on clem
Repository revision: 7ef18c6ea5b2cb6450c0f960445b26cad03d200e