Run "summary" after opening new mailbox.

Issue diagnostics if mailbox cannot be opened.
Display mailbox summary when called without arguments.

@@ -17,6 +17,8 @@
 
 #include "mail.h"
 
+static char *prev_name;
+
 /*
  * fi[le] [file]
  * fold[er] [file]
@@ -27,25 +29,23 @@ mail_file (int argc, char **argv)
 {
   if (argc == 1)
     {
-      url_t url;
-
-      mailbox_get_url (mbox, &url);
-      fprintf (ofile, "%s\n", url_to_string (url));
-      
-      /*FIXME: display current folder info */
+      mail_summary (0, NULL);
     }
   else if (argc == 2)
     {
+      char *pname;
+      url_t url;
+
       /* switch folders */
       /*
        * special characters:
        * %	system mailbox
-       * %user	system mailbox of user
+       * %user	system mailbox of the user
        * #	the previous file
        * &	the current mbox
        * +file	the file named in the folder directory (set folder=foo)
        */
-      mailbox_t newbox;
+      mailbox_t newbox = NULL;
       struct mail_env_entry *env;
       char *name;
       
@@ -62,8 +62,13 @@ mail_file (int argc, char **argv)
 	  break;
 	  
 	case '#':
-	  util_error("# notation not supported");
+	  if (!prev_name)
+	    {
+	      util_error("No previous file");
 	  return 1;
+	    }
+	  name = prev_name;
+	  break;
 	  
 	case '&':
 	  name = getenv ("MBOX");
@@ -81,23 +86,38 @@ mail_file (int argc, char **argv)
 	  name = argv[1];
 	}
       
-      if (mailbox_create_default (&newbox, name) != 0)
-	return 1;
-      if (mailbox_open (newbox, MU_STREAM_READ) != 0)
-	return 1;
+      if (mailbox_create_default (&newbox, name) != 0 
+	  || mailbox_open (newbox, MU_STREAM_READ) != 0)
+	{
+	  mailbox_destroy (&newbox);
+	  util_error("can't open mailbox %s: %s",
+		     name ? name : "%", strerror(errno));
+	  return 1;
+	}
 
+      mailbox_get_url (mbox, &url);
+      pname = strdup (url_to_string (url));
       if (mail_mbox_close ())
 	{
+	  if (pname)
+	    free (pname);
 	  mailbox_close (newbox);
 	  mailbox_destroy (&newbox); 
 	  return 1;
 	}
       
+      if (prev_name)
+	free (prev_name);
+      prev_name = pname;
+      
       mbox = newbox;
       mailbox_messages_count (mbox, &total);
       cursor = realcursor = 1;
       if ((util_find_env("header"))->set)
+	{
+	  util_do_command ("summary");
 	util_do_command ("z.");
+	}
       return 0;
     }
   else