Fix the use of deprecated Guile interfaces in port code.

* am/guile.m4 (MU_CHECK_GUILE): Check for SCM_DEVAL_P et al.
* libmu_scm/mu_guile.c (mu_guile_init): Protect calls to
SCM_DEVAL_P &c. by #ifdef GUILE_DEBUG_MACROS
* libmu_scm/mu_port.c [!HAVE_SCM_T_OFF](scm_t_off): New typedef.
(mu_port_make_from_stream): Use scm_new_port_table_entry instead
of the deprecated scm_add_to_port_table

@@ -63,6 +63,17 @@ AC_DEFUN([MU_CHECK_GUILE],
     GUILE_VERSION_NUMBER=
     m4_if($3,,[AC_MSG_ERROR(required library libguile not found)], [$3])
   else
+    AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[#include <libguile.h>]],
+                      [SCM_DEVAL_P = 1;
+                       SCM_BACKTRACE_P = 1;
+                       SCM_RECORD_POSITIONS_P = 1;
+                       SCM_RESET_DEBUG_MODE;])],
+                      [mu_cv_guile_debug=yes],
+                      [mu_cv_guile_debug=no])
+    if test $mu_cv_guile_debug = yes; then
+      AC_DEFINE_UNQUOTED(GUILE_DEBUG_MACROS, 1,
+                         [Define to 1 if SCM_DEVAL_P, SCM_BACKTRACE_P, SCM_RECORD_POSITIONS_P and SCM_RESET_DEBUG_MODE are defined])
+    fi
     AC_CHECK_TYPES([scm_t_off],[],[],[#include <libguile.h>])
     AC_DEFINE_UNQUOTED(GUILE_VERSION, "$GUILE_VERSION",
                        [Guile version number])

@@ -109,10 +109,12 @@ mu_guile_init (int debug)
 
   if (debug)
     {
+#ifdef GUILE_DEBUG_MACROS
       SCM_DEVAL_P = 1;
       SCM_BACKTRACE_P = 1;
       SCM_RECORD_POSITIONS_P = 1;
       SCM_RESET_DEBUG_MODE;
+#endif
     }
   mu_scm_init ();
 }

@@ -20,6 +20,10 @@
 #include "mu_scm.h"
 #include <mailutils/io.h>
 
+#ifndef HAVE_SCM_T_OFF
+typedef off_t scm_t_off;
+#endif
+
 struct mu_port
 {
   mu_stream_t stream;         /* Associated stream */
@@ -87,16 +91,13 @@ mu_port_make_from_stream (SCM msg, mu_stream_t stream, long mode)
   mp->stream = stream;
   mp->offset = 0;
 
-  port = scm_cell (scm_tc16_smuport | mode, 0);
-
-  pt = scm_add_to_port_table (port);
-  SCM_SETPTAB_ENTRY (port, pt);
+  port = scm_new_port_table_entry (scm_tc16_smuport | mode);
+  pt = SCM_PTAB_ENTRY (port);
   pt->rw_random = mu_stream_is_seekable (stream);
-
   SCM_SETSTREAM (port, mp);
   mu_port_alloc_buffer (port, 0, 0);
-
-  /*  SCM_PTAB_ENTRY (port)->file_name = "name";FIXME*/
+  /* FIXME:
+     SCM_PTAB_ENTRY (port)->file_name = "name";*/
   return port;
 }