Enable GSASL by default.

* am/gsasl.m4 (MU_CHECK_GSASL): Enable GSASL by default.  Other minor fixes.
* am/tls.m4 (MU_CHECK_TLS): Rename to MU_CHECK_GNUTLS.  Check option
arguments.  Check for gnutls library version.
* configure.ac: Update.
* README: Document the change.
* NEWS: Document the change.

-GNU mailutils NEWS -- history of user-visible changes. 2011-11-21
+GNU mailutils NEWS -- history of user-visible changes. 2011-11-23
 Copyright (C) 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011
 Free Software Foundation, Inc.
 See the end of file for copying conditions.
@@ -147,6 +147,15 @@ all available DBM libraries it can use.
 
 ** Imap and nntp clients are not yet implemented
 
+** Link with GSASL by default
+
+GSASL is used by several Mailutils components (notably pop3d
+and imap4d as well as their client counterparts) for authentification.
+Since this version, it is enabled by default if configure detects the
+presense of GNU SASL version 0.2.3 or later.
+
+This can be disabled using the --without-gsasl option.
+
 ** Experimental features
 
 The C++ and Python bindings are considered experimental and unstable.

@@ -156,11 +156,14 @@ mailutils-specific configuration options:
 	Disable the TLS/SSL encryption via GnuTLS (a Transport Layer
 	Security Library) in IMAP4/POP3 daemons and utilities.
 
-    --with-gsasl
+    --without-gsasl
 
-	Enable GNU SASL support (Simple Authentication and Security
-	Layer framework). IMAP4d supports this mechanism. This
-	requires GSASL version 0.2.3 or newer. 
+	Disable GNU SASL support.
+
+	GSASL is used by several Mailutils components (notably pop3d
+	and imap4d as well as their client counterparts) for
+	authentification.  It is enabled by default if configure
+	detects the presense of GNU SASL version 0.2.3 or later.
 
     --with-gssapi
 

@@ -14,20 +14,20 @@ dnl
 dnl You should have received a copy of the GNU General Public License along
 dnl with GNU Mailutils.  If not, see <http://www.gnu.org/licenses/>.
 dnl
+
+dnl MU_CHECK_GSASL([VERSION = `'],[ACTION-IF-TRUE=`'],[ACTION-IF-FALSE=`']
 AC_DEFUN([MU_CHECK_GSASL],
-[AC_CACHE_CHECK([whether to use GNU SASL library],
-                 [mu_cv_lib_gsasl],
- [if test "x$mu_cv_lib_gsasl" = x; then
+[if test "x$mu_cv_lib_gsasl" = x; then
    cached=""
    mu_cv_lib_gsasl=no
 
    AC_ARG_WITH(gsasl,
-     AC_HELP_STRING([--with-gsasl], [use libgsasl for SASL authentication]),
+     AC_HELP_STRING([--without-gsasl], [do not use libgsasl]),
      [case $withval in
       yes|no) wantgsasl=$withval;;
       *) AC_MSG_ERROR([bad value for --with-gsasl: $withval]);;
       esac],
-     [wantgsasl=no])
+     [wantgsasl=yes])
 
    if test $wantgsasl = yes; then
      AC_CHECK_HEADER(gsasl.h,
@@ -56,9 +56,17 @@ main()
        LIBS=$save_LIBS
      fi       
    fi
-  fi])
+ else
+  cached=" (cached) "
+ fi
  if test $mu_cv_lib_gsasl != no; then
    GSASL_LIBS=$mu_cv_lib_gsasl
-   ifelse([$2],,,[$2])
+   m4_if([$2],,,[$2])
+ fi
+ m4_if([$3],,,[if test $mu_cv_lib_gsasl = no; then
+   $3
  fi])
+ AC_MSG_CHECKING([whether to use GSASL])
+ AC_MSG_RESULT(${cached}${mu_cv_lib_gsasl})
+ ])
  

@@ -15,34 +15,62 @@ dnl
 dnl You should have received a copy of the GNU General Public License along
 dnl with GNU Mailutils.  If not, see <http://www.gnu.org/licenses/>.
 dnl
-AC_DEFUN([MU_CHECK_TLS],
+
+dnl MU_CHECK_GNUTLS([VERSION = `'],[ACTION-IF-TRUE=`'],[ACTION-IF-FALSE=`']
+AC_DEFUN([MU_CHECK_GNUTLS],
 [
- if test "x$WITH_GNUTLS" = x; then
+ if test "x$mu_cv_lib_gnutls" = x; then
    cached=""
    AC_ARG_WITH([gnutls],
                AC_HELP_STRING([--without-gnutls],
                               [do not use GNU TLS library]),
-               [WITH_GNUTLS=$withval],
-               [WITH_GNUTLS=yes])
+               [case "$withval" in
+	        yes|no) mu_cv_lib_gnutls=$withval;;
+	        *) AC_MSG_ERROR([bad value for --with-gnutls: $withval]);;
+                esac],
+               [mu_cv_lib_gnutls=yes])
 
-   if test "$WITH_GNUTLS" != "no"; then
+   if test "$mu_cv_lib_gnutls" != "no"; then
      AC_CHECK_HEADER(gnutls/gnutls.h,
                      [:],
-                     [WITH_GNUTLS=no])
-     if test "$WITH_GNUTLS" != "no"; then
+                     [mu_cv_lib_gnutls=no])
+     if test "$mu_cv_lib_gnutls" != "no"; then
        saved_LIBS=$LIBS
        AC_CHECK_LIB(gcrypt, main,
                     [TLS_LIBS="-lgcrypt"],
-                    [WITH_GNUTLS=no])
+                    [mu_cv_lib_gnutls=no])
        LIBS="$LIBS $TLS_LIBS"
        AC_CHECK_LIB(gnutls, gnutls_global_init,
                     [TLS_LIBS="-lgnutls $TLS_LIBS"],
-                    [WITH_GNUTLS=no])
+                    [mu_cv_lib_gnutls=no])
        LIBS=$saved_LIBS
+       m4_if([$1],,,[if test $mu_cv_lib_gnutls != no; then
+         LIBS="$LIBS $TLS_LIBS"
+         AC_TRY_RUN([
+#include <gnutls/gnutls.h>
+
+int
+main()
+{
+  return gnutls_check_version ("$1") == (char*) 0;
+}],
+                    [:],
+                    [mu_cv_lib_gnutls=no],
+                    [mu_cv_lib_gnutls=no])
+         LIBS=$saved_LIBS
+       fi])
      fi
    fi
  else
   cached=" (cached) "
  fi
- AC_MSG_CHECKING([whether to use TLS libraries])
- AC_MSG_RESULT(${cached}${WITH_GNUTLS})])
+ 
+ m4_if([$2],,,[if test $mu_cv_lib_gnutls != no; then
+   $2
+ fi])
+ m4_if([$3],,,[if test $mu_cv_lib_gnutls = no; then
+   $3
+ fi])
+ 
+ AC_MSG_CHECKING([whether to use GNU TLS])
+ AC_MSG_RESULT(${cached}${mu_cv_lib_gnutls})])

@@ -251,13 +251,13 @@ AC_SUBST(SERV_AUTHLIBS)
 AC_SUBST(SERV_AUTHINCS)
 
 AC_ARG_WITH([gssapi],
-            AC_HELP_STRING([--with-gssapi],
+            AC_HELP_STRING([--with-gssapi@<:@=PATH@:>@],
                            [use GSSAPI authentication]),
-            [WITH_GSSAPI=$withval],
-            [WITH_GSSAPI=no])
+            [status_gssapi=$withval],
+            [status_gssapi=no])
 
-if test "x$WITH_GSSAPI" != "xno"; then
-  MU_CHECK_GSSAPI($WITH_GSSAPI)
+if test "x$status_gssapi" != "xno"; then
+  MU_CHECK_GSSAPI($status_gssapi)
   if test "$GSSAPI_IMPL" = "none"; then
     AC_CACHE_SAVE
     AC_MSG_RESULT([GSSAPI libraries not found])
@@ -299,19 +299,19 @@ AC_SUBST(SITE_CRAM_MD5_PWD,"\$(sysconfdir)/cram-md5.pwd")
 
 AC_ARG_WITH(cram-passwd,
             AC_HELP_STRING([--with-cram-passwd=FILE],
-                           [use keep passwords for CRAM-MD5 authentication method in FILE (default $SITE_CRAM_MD5_PWD)]),
+                           [keep passwords for CRAM-MD5 authentication method in FILE (default $SITE_CRAM_MD5_PWD)]),
             [case "${withval}" in
             /*) SITE_CRAM_MD5_PWD="${withval}";;
             ./*|../*) AC_MSG_ERROR(Bad value for --with-cram-passwd);;
             *)  SITE_CRAM_MD5_PWD="\$(sysconfdir)/${withval}";;
             esac])
 
-MU_CHECK_TLS
-if test "$WITH_GNUTLS" != "no"; then
+MU_CHECK_GNUTLS([1.2.1],[
   MU_AUTHLIBS="$MU_AUTHLIBS $TLS_LIBS"
   AC_DEFINE(WITH_GNUTLS,1,[Define if mailutils is using GNU TLS])
   AC_DEFINE(WITH_TLS,1,[Define if mailutils is using TLS])
-fi
+  status_gnutls=yes
+])
 
 AC_SUBST(SITE_MAIL_RC)
 AC_ARG_WITH([mail-rc],
@@ -1394,9 +1394,9 @@ status_pam=$status_pam
 status_ltdl=$status_ltdl
 status_dbm="$status_dbm"
 status_ldap=$status_ldap
-status_gnutls=$WITH_GNUTLS
+status_gnutls=$status_gnutls
 status_gsasl=$status_gsasl
-status_gssapi=$WITH_GSSAPI
+status_gssapi=$status_gssapi
 status_guile=$useguile
 status_python=$status_python
 status_cxx=$mu_cv_enable_cxx