Remove the use of MAXHOSTNAMELEN macro.

* comsat/comsat.c (hostname): Change type.
(comsat_init): Use mu_get_host_name.
* comsat/comsat.h (hostname): Change declaration.
* libmailutils/locker.c (lock_dotlock): Use mu_get_host_name.
* libmailutils/mutil.c (mu_get_host_name): Rewrite.
* pop3d/pop3d.c (pop3d_mainloop): Remove unnecessary call to
gethostbyname.
* pop3d/pop3d.h (MAXHOSTNAMELEN): Remove definition.

@@ -97,12 +97,8 @@ static const char *comsat_argp_capa[] = {
 #define NOT_HERE 1
 #define PERMISSION_DENIED 2
 
-#ifndef MAXHOSTNAMELEN
-# define MAXHOSTNAMELEN 64
-#endif
-
 int maxlines = 5;
-char hostname[MAXHOSTNAMELEN];
+char *hostname;
 const char *username;
 int require_tty;
 mu_m_server_t server;
@@ -190,11 +186,17 @@ sig_hup (int sig)
 void
 comsat_init ()
 {
+  int rc;
+
   /* Register mailbox formats */
   mu_register_all_mbox_formats ();
 
-  gethostname (hostname, sizeof hostname);
-
+  rc = mu_get_host_name (&hostname);
+  if (rc)
+    {
+      mu_diag_funcall (MU_DIAG_ERROR, "mu_get_host_name", NULL, rc);
+      exit (EXIT_FAILURE);
+    } 
   /* Set signal handlers */
   signal (SIGTTOU, SIG_IGN);
   signal (SIGCHLD, SIG_IGN);
@@ -556,7 +558,7 @@ main (int argc, char **argv)
   
   if (mu_app_init (&argp, comsat_argp_capa, comsat_cfg_param, argc, argv, 0,
 		   &ind, server))
-    exit (1);
+    exit (EXIT_FAILURE);
 
   if (test_mode)
     {

@@ -75,7 +75,7 @@ extern time_t overflow_control_interval;
 extern time_t overflow_delay_time;
 extern int maxlines;
 extern const char *username;
-extern char hostname[];
+extern char *hostname;
 extern struct daemon_param daemon_param;
 
 void run_user_action (FILE *tty, const char *cr, mu_message_t msg);

@@ -704,14 +704,11 @@ destroy_dotlock (mu_locker_t locker)
   free (locker->data.dot.nfslock);
 }
 
-#ifndef MAXHOSTNAMELEN
-# define MAXHOSTNAMELEN 256
-#endif
-
 static int
 lock_dotlock (mu_locker_t locker, enum mu_locker_mode mode)
 {
-  char host[MAXHOSTNAMELEN + 1] = "localhost";
+  int rc;
+  char *host = NULL;
   char pid[11];		/* 10 is strlen(2^32 = 4294967296) */
   char now[11];
   size_t sz = 0;
@@ -729,8 +726,9 @@ lock_dotlock (mu_locker_t locker, enum mu_locker_mode mode)
 
   /* build the NFS hitching-post to the lock file */
 
-  gethostname (host, sizeof (host));
-  host[MAXHOSTNAMELEN] = 0;
+  rc = mu_get_host_name (&host);
+  if (rc)
+    return rc;
 
   snprintf (now, sizeof (now), "%lu", (unsigned long) time (0));
   now[sizeof (now) - 1] = 0;
@@ -746,10 +744,14 @@ lock_dotlock (mu_locker_t locker, enum mu_locker_mode mode)
   locker->data.dot.nfslock = malloc (sz);
   
   if (!locker->data.dot.nfslock)
-    return ENOMEM;
-  
+    {
+      free (host);
+      return ENOMEM;
+    }
+
   snprintf (locker->data.dot.nfslock, sz, "%s.%s.%s.%s",
 	    locker->file, pid, now, host);
+  free (host);
   
   fd = open (locker->data.dot.nfslock,
 	     O_WRONLY | O_CREAT | O_EXCL, LOCKFILE_ATTR);

@@ -291,30 +291,80 @@ mu_cpystr (char *dst, const char *src, size_t size)
   return len;
 }
 
+#ifndef MAXHOSTNAMELEN
+# define MAXHOSTNAMELEN 64
+#endif
+
 int
 mu_get_host_name (char **host)
 {
-  char hostname[MAXHOSTNAMELEN + 1];
-  struct hostent *hp = NULL;
-  char *domain = NULL;
-
-  gethostname (hostname, sizeof hostname);
-  hostname[sizeof (hostname) - 1] = 0;
-
-  if ((hp = gethostbyname (hostname)))
-    domain = hp->h_name;
-  else
-    domain = hostname;
-
-  domain = strdup (domain);
-
-  if (!domain)
-    return ENOMEM;
+  char *hostname = NULL;
+  size_t size = 0;
+  char *p;
 
-  *host = domain;
+  while (1)
+    {
+      if (size == 0)
+	{
+	  size = MAXHOSTNAMELEN;
+	  p = malloc (size);
+	}
+      else
+	{
+	  size_t ns = size * 2;
+	  if (ns < size)
+	    {
+	      free (hostname);
+	      return ENOMEM;
+	    }
+	  size = ns;
+	  p = realloc (hostname, size);
+	}
+      if (!p)
+	{
+	  free (hostname);
+	  return ENOMEM;
+	}
+      hostname = p;
+      hostname[size - 1] = 0;
+      if (gethostname (hostname, size - 1) == 0)
+	{
+	  if (!hostname[size - 1])
+	    break;
+	}
+      else if (errno != 0 && errno != ENAMETOOLONG && errno != EINVAL
+	       && errno != ENOMEM)
+	{
+	  int rc = errno;
+	  free (hostname);
+	  return rc;
+	}
+    }
 
+  /* Try to return fully qualified host name */
+  if (!strchr (hostname, '.'))
+    {
+      struct hostent *hp = gethostbyname (hostname);
+      if (hp)
+	{
+	  size_t len = strlen (hp->h_name);
+	  if (size < len + 1)
+	    {
+	      p = realloc (hostname, len + 1);
+	      if (!p)
+		{
+		  free (hostname);
+		  return ENOMEM;
+		}
+	      hostname = p;
+	    }
+	  strcpy (hostname, hp->h_name);
+	}
+    }
+  
+  *host = hostname;
   return 0;
-}
+}  
 
 /*
  * Functions used to convert unix mailbox/user names into RFC822 addr-specs.

@@ -227,19 +227,13 @@ pop3d_mainloop (int ifd, int ofd)
   /* Prepare the shared secret for APOP.  */
   {
     char *local_hostname;
-    local_hostname = mu_alloc (MAXHOSTNAMELEN + 1);
-
-    /* Get our canonical hostname. */
-    {
-      struct hostent *htbuf;
-      gethostname (local_hostname, MAXHOSTNAMELEN);
-      htbuf = gethostbyname (local_hostname);
-      if (htbuf)
-	{
-	  free (local_hostname);
-	  local_hostname = strdup (htbuf->h_name);
-	}
-    }
+    
+    status = mu_get_host_name (&local_hostname);
+    if (status)
+      {
+        mu_diag_funcall (MU_DIAG_ERROR, "mu_get_host_name", NULL, status);
+        exit (EXIT_FAILURE);
+      }
 
     md5shared = mu_alloc (strlen (local_hostname) + 51);
 

@@ -133,12 +133,6 @@ extern int expire_on_exit;
 #include <shadow.h>
 #endif
 
-#ifndef MAXHOSTNAMELEN
-/* Maximum length of a hostname (is this defined somewhere else?).  */
-/* MAXHOSTNAMELEN is already defined on Solaris.  */
-# define MAXHOSTNAMELEN	64
-#endif
-
 #define POP3_ATTRIBUTE_DELE 0x0001
 #define POP3_ATTRIBUTE_RETR 0x0010