bug#9017: 24.0.50; gnutls.c: [0] (Emacs) fatal error: Key usage violation in certificate has been detected.

[Roland Winkler]

Today I recompiled emacs from the trunk. Since then I cannot send
emails anymore. Instead I get the error message

gnutls.c: [0] (Emacs) fatal error: Key usage violation in certificate has been 
detected.
gnutls.el: (err=[-48] Key usage violation in certificate has been detected.) 
boot: (:priority NORMAL :hostname foo.bar.com :loglevel 0 :trustfiles 
(/etc/ssl/certs/ca-certificates.crt) :crlfiles nil :keylist nil :verify-flags 
nil :verify-error nil :verify-hostname-error nil :callbacks nil)
gnutls-negotiate: GnuTLS error: #<process smtpmail>, -48
gnutls.c: [0] (Emacs) fatal error: An unexpected TLS handshake packet was 
received. [922 times]

Previously, I had no such problems.

In GNU Emacs 24.0.50.1 (x86_64-unknown-linux-gnu, GTK+ Version 2.20.1)
 of 2011-07-07 on regnitz
Windowing system distributor `The X.Org Foundation', version 11.0.10706000

Important settings:
  value of $LC_ALL: nil
  value of $LC_COLLATE: C
  value of $LC_CTYPE: nil
  value of $LC_MESSAGES: nil
  value of $LC_MONETARY: nil
  value of $LC_NUMERIC: nil
  value of $LC_TIME: en_GB.utf8
  value of $LANG: en_US.ISO-8859-15
  value of $XMODIFIERS: nil
  locale-coding-system: iso-latin-9-unix
  default enable-multibyte-characters: t