Add useful debugging hooks.

* libmailutils/diag/bt.c: New file.
* libmailutils/diag/wd.c: New file.
* libmailutils/diag/Makefile.am (libdiag_la_SOURCES): Add bt.c and wd.c

* include/mailutils/debug.h (mu_gdb_bt, mu_wd): New protos.
* include/mailutils/util.h (mu_getmaxfd): New protos.
* libmailutils/base/getmaxfd.c: New file.
* libmailutils/base/Makefile.am (libbase_la_SOURCES): Add getmaxfd.c

* libmailutils/server/acl.c: Use mu_getmaxfd.
* libmailutils/stream/prog_stream.c: Likewise.
* mh/mh_whatnow.c: Likewise.

* libmu_scm/mu_body.c (mu-body?): Bugfix.

@@ -83,7 +83,6 @@ void mu_debug_log_begin (const char *fmt, ...) MU_PRINTFLIKE(1,2);
 void mu_debug_log_cont (const char *fmt, ...) MU_PRINTFLIKE(1,2);
 void mu_debug_log_end (const char *fmt, ...) MU_PRINTFLIKE(1,2);
 void mu_debug_log_nl (void);
-
   
   
 #define MU_ASSERT(expr)						\
@@ -115,7 +114,13 @@ void mu_debug_log_nl (void);
 	  mu_debug_log s;						 \
       }                                                                  \
   while (0)
- 
+
+  /* Debugging hooks. */
+  /* Dump a stack trace and terminate the program. */
+void mu_gdb_bt (void);
+  /* Sleep till attached to by gdb. */
+void mu_wd (unsigned to);
+  
 #ifdef __cplusplus
 }
 #endif

@@ -177,6 +177,7 @@ int mu_getpass (mu_stream_t in, mu_stream_t out, const char *prompt,
   /* ----------------------- */
   /* Assorted functions.     */
   /* ----------------------- */
+int mu_getmaxfd (void);
 /* Get the host name, doing a gethostbyname() if possible. */
 int mu_get_host_name (char **host);
 int mu_spawnvp (const char *prog, char *av[], int *stat);

@@ -31,6 +31,7 @@ libbase_la_SOURCES = \
  filename.c\
  freeitem.c\
  getcwd.c\
+ getmaxfd.c\
  getpass.c\
  hostname.c\
  iterator.c\

+/* GNU Mailutils -- a suite of utilities for electronic mail
+   Copyright (C) 2011 Free Software Foundation, Inc.
+
+   This library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 3 of the License, or (at your option) any later version.
+
+   This library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General
+   Public License along with this library.  If not, see 
+   <http://www.gnu.org/licenses/>. */
+
+#ifdef HAVE_CONFIG_H
+# include <config.h>
+#endif
+
+#include <unistd.h>
+#include <limits.h>
+
+#if defined (HAVE_SYSCONF) && defined (_SC_OPEN_MAX)
+# define __getmaxfd() sysconf (_SC_OPEN_MAX)
+#elif defined (HAVE_GETDTABLESIZE)
+# define __getmaxfd() getdtablesize ()
+#elif defined OPEN_MAX
+# define __getmaxfd() OPEN_MAX
+#else
+# define __getmaxfd() 256
+#endif
+
+int
+mu_getmaxfd ()
+{
+  return __getmaxfd ();
+}
+

@@ -18,11 +18,13 @@
 noinst_LTLIBRARIES = libdiag.la
 
 libdiag_la_SOURCES = \
+ bt.c\
  debug.c\
  diag.c\
  muerror.c\
  muerrno.c\
- syslog.c
+ syslog.c\
+ wd.c
 
 INCLUDES = @MU_LIB_COMMON_INCLUDES@ -I/libmailutils
 

+/* GNU Mailutils -- a suite of utilities for electronic mail
+   Copyright (C) 2011 Free Software Foundation, Inc.
+
+   This library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 3 of the License, or (at your option) any later version.
+
+   This library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General
+   Public License along with this library.  If not, see 
+   <http://www.gnu.org/licenses/>. */
+
+#ifdef HAVE_CONFIG_H
+# include <config.h>
+#endif
+
+#include <sys/types.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <string.h>
+#include <argp.h>
+#include <mailutils/util.h>
+
+/* Dump a stack trace and terminate current program.
+
+   The trace is written to file /tmp/mailutils.PROG.PID, where PROG
+   is the file name of the program, and PID its PID. */
+   
+void
+mu_gdb_bt ()
+{
+  int i;
+  pid_t master_pid = getpid ();
+  pid_t pid;
+  static char buf[1024];
+  static char fname[1024];
+  char *p;
+  int fd;
+  char *argv[8];
+  
+  p = strrchr (program_invocation_name, '/');
+  if (p)
+    p++;
+  else
+    p = program_invocation_name;
+  sprintf (fname, "/tmp/mailutils.%s.%lu", p, (unsigned long) master_pid);
+  
+  pid = fork ();
+  if (pid == (pid_t)-1)
+    abort ();
+  if (pid)
+    {
+      sleep (10);
+      abort ();
+    }
+
+  for (i = mu_getmaxfd (); i >= 0; i--)
+    close (i);
+
+  fd = open (fname, O_WRONLY|O_CREAT, 0600);
+  if (fd == -1)
+    abort ();
+
+  dup2 (fd, 1);
+  dup2 (fd, 2);
+  close (fd);
+  
+  argv[0] = "/usr/bin/gdb";
+  argv[1] = program_invocation_name;
+  sprintf (buf, "%lu", (unsigned long) master_pid);
+  argv[2] = buf;
+  argv[3] = "-ex";
+  argv[4] = "bt";
+  argv[5] = "-ex";
+  argv[6] = "kill";
+  argv[7] = NULL;
+
+  execvp (argv[0], argv);
+  abort ();
+}
+

+/* GNU Mailutils -- a suite of utilities for electronic mail
+   Copyright (C) 2011 Free Software Foundation, Inc.
+
+   This library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 3 of the License, or (at your option) any later version.
+
+   This library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General
+   Public License along with this library.  If not, see 
+   <http://www.gnu.org/licenses/>. */
+
+#ifdef HAVE_CONFIG_H
+# include <config.h>
+#endif
+
+#include <unistd.h>
+#include <argp.h>
+#include <mailutils/diag.h>
+
+/* A debugging hook.
+
+   Suspend execution to let the developer to attach to the current process
+   using gdb.
+
+   Wait at most TO seconds.  If TO is 0, wait forever. */
+
+void
+mu_wd (unsigned to)
+{
+  unsigned volatile _count_down;
+  pid_t pid = getpid ();
+
+  if (to)
+    mu_diag_output (MU_DIAG_CRIT,
+		    "process %lu is waiting for debug (%u seconds left)",
+		    (unsigned long) pid, to);
+  else
+    mu_diag_output (MU_DIAG_CRIT,
+		    "process %lu is waiting for debug",
+		    (unsigned long) pid);
+  mu_diag_output (MU_DIAG_CRIT,
+		  "to attach: gdb -ex 'set variable mu_wd::_count_down=0' %s %lu",
+		  program_invocation_name, (unsigned long) pid);
+  if (to)
+    {
+      _count_down = to;
+      while (_count_down)
+	{
+	  sleep (1);
+	  _count_down--;
+	}
+    }
+  else
+    {
+      _count_down = 1;
+      while (_count_down)
+	{
+	  sleep (1);
+	}
+    }
+  mu_diag_output (MU_DIAG_CRIT, "process %lu finished waiting",
+		  (unsigned long) pid);
+}

@@ -39,6 +39,7 @@
 #include <mailutils/errno.h>
 #include <mailutils/kwd.h>
 #include <mailutils/io.h>
+#include <mailutils/util.h>
 
 struct _mu_acl_entry
 {
@@ -473,14 +474,6 @@ struct run_closure
   mu_acl_result_t *result;
 };
 
-#if defined (HAVE_SYSCONF) && defined (_SC_OPEN_MAX)
-# define getmaxfd() sysconf (_SC_OPEN_MAX)
-#elif defined (HAVE_GETDTABLESIZE)
-# define getmaxfd() getdtablesize ()
-#else
-# define getmaxfd() 64
-#endif
-
 #define SEQ(s, n, l) \
   (((l) == (sizeof(s) - 1)) && memcmp (s, n, l) == 0)
 
@@ -604,7 +597,7 @@ spawn_prog (const char *cmdline, int *pstatus, struct run_closure *rp)
 	  _exit (127);
 	}
       
-      for (i = getmaxfd (); i > 2; i--)
+      for (i = mu_getmaxfd (); i > 2; i--)
 	close (i);
       execvp (ws.ws_wordv[0], ws.ws_wordv);
       _exit (127);

@@ -60,14 +60,6 @@ _prog_stream_unregister (struct _mu_prog_stream *stream)
 
 
 
-#if defined (HAVE_SYSCONF) && defined (_SC_OPEN_MAX)
-# define getmaxfd() sysconf (_SC_OPEN_MAX)
-#elif defined (HAVE_GETDTABLESIZE)
-# define getmaxfd() getdtablesize ()
-#else
-# define getmaxfd() 64
-#endif
-
 #define REDIRECT_STDIN_P(f) ((f) & MU_STREAM_WRITE)
 #define REDIRECT_STDOUT_P(f) ((f) & MU_STREAM_READ)
 
@@ -260,7 +252,7 @@ start_program_filter (int *p, struct _mu_prog_stream *fs, int flags)
 	}
        
       /* Close unneded descripitors */
-      for (i = getmaxfd (); i > 2; i--)
+      for (i = mu_getmaxfd (); i > 2; i--)
 	close (i);
 
       /*FIXME: Switch to other uid/gid if desired */

@@ -100,7 +100,7 @@ SCM_DEFINE_PUBLIC (scm_mu_body_p, "mu-body?", 1, 0, 0,
 "Return @code{true} if @var{scm} is a Mailutils message body object.\n")
 #define FUNC_NAME s_scm_mu_body_p
 {
-  return mu_scm_is_body (scm);
+  return scm_from_bool (mu_scm_is_body (scm));
 }
 #undef FUNC_NAME
 

@@ -17,14 +17,6 @@
 
 #include <mh.h>
 
-#if defined (HAVE_SYSCONF) && defined (_SC_OPEN_MAX)
-# define getmaxfd() sysconf (_SC_OPEN_MAX)
-#elif defined (HAVE_GETDTABLESIZE)
-# define getmaxfd() getdtablesize ()
-#else
-# define getmaxfd() 64
-#endif
-
 typedef int (*handler_fp) (struct mh_whatnow_env *wh,
 			   int argc, char **argv,
 			   int *status);
@@ -620,7 +612,7 @@ mh_whatnowproc (struct mh_whatnow_env *wh, int initial_edit, const char *prog)
       
       set_default_editor (wh);
       mh_whatnow_env_to_environ (wh);
-      for (i = getmaxfd (); i > 2; i--)
+      for (i = mu_getmaxfd (); i > 2; i--)
 	close (i);
       execvp (ws.ws_wordv[0], ws.ws_wordv);
       mu_diag_funcall (MU_DIAG_ERROR, "execvp", prog, errno);