comsatd: optional argument to the --test option supplies the name of the tty to use

* NEWS: Document changes.
* comsat/action.c (open_default_tty): Remove.
(open_tty): Examine the tty device (or file) and construct a suitable
filter chain.
Use append mode when opening it.
* comsat/comsat.c: The --test option takes optional argument.
* comsat/tests/testsuite.at: Use local file instead of the tty.
* doc/texinfo/programs/comsatd.texi: Document changes.

5 files changed, 153 insertions, 132 deletions

diff --git a/NEWS b/NEWS
index 251f5a80b..50eadb89a 100644
--- a/NEWS
+++ b/NEWS
@@ -1,37 +1,42 @@
-GNU mailutils NEWS -- history of user-visible changes. 2019-08-29
+GNU mailutils NEWS -- history of user-visible changes. 2019-09-03
 Copyright (C) 2002-2019 Free Software Foundation, Inc.
 See the end of file for copying conditions.
 
 Please send mailutils bug reports to <bug-mailutils@gnu.org>.
 
 Version 3.7.90 (git)
 
 * Use of TLS in pop3d run from inetd
 
 New global configuration statement "tls-mode" configures the TLS for
 use in inetd mode.
     
 The certificate and key files are configured by the global "tls"
 compound statement.
     
 Example configuration (pop3s server):
     
   mode inetd;
   tls-mode connection;
   tls {
       ssl-key-file /etc/ssl/key.pem;
       ssl-certificate-file /etc/ssl/cert.pem;
   }
 
+* comsatd --test
+
+The --test option takes optional argument: name of the tty or file to
+use for reporting.
+  
 
 Version 3.7 - 2019-06-21
 
 * Support for the new mailbox format - dotmail
 
 Dotmail is a replacement for traditional mbox format, proposed by
 Kurt Hackenberg. A dotmail mailbox is a single disk file, where
 messages are stored sequentially. Each message ends with a single
 dot (similar to the format used in the SMTP DATA command). Any dot
 appearing at the start of the line is doubled, to prevent it from
 being interpreted as end of message marker.
 
diff --git a/comsat/action.c b/comsat/action.c
index c9703f28e..b6799c481 100644
--- a/comsat/action.c
+++ b/comsat/action.c
@@ -167,138 +167,148 @@ expand_line (const char *str, mu_message_t msg)
         }
     }
   mu_opool_append_char (pool, 0);
   str = strdup (mu_opool_finish (pool, NULL));
   mu_opool_destroy (&pool);
   return (char *)str;
 }
 
 const char *default_action =
 #include "biff.rc.h"
 ;
 
+/* Examine the tty to determine which filters to apply when printing
+   to it.  On entry, STR is the opened stream, FLT points to an array
+   of char* with at least 3 slots, and NFLT to an integer number.
+   On success, populates FLT with the necessary filter chain, and stores
+   to *NFLT the number of used slots. On error, issues error message and
+   returns -1.
+   FLT and NFLT can be used as input to mu_filter_chain_create.
+ */
 static int
-need_crlf (mu_stream_t str)
+study_tty (mu_stream_t str, char *flt[], int *nflt)
 {
-#if defined(OPOST) && defined(ONLCR)
   mu_transport_t trans[2];
-  struct termios tbuf;
+  int fd;
+  struct stat st;
+  int rc;
 
-  if (mu_stream_ioctl (str, MU_IOCTL_TRANSPORT, MU_IOCTL_OP_GET, trans))
-    return 1; /* suppose we do need it */
-  if (tcgetattr ((int) (intptr_t) trans[0], &tbuf) == 0 &&
-      (tbuf.c_oflag & OPOST) && (tbuf.c_oflag & ONLCR))
-    return 0;
-  else
-    return 1;
+  rc = mu_stream_ioctl (str, MU_IOCTL_TRANSPORT, MU_IOCTL_OP_GET, trans);
+  if (rc)
+    {
+      mu_diag_funcall (MU_DIAG_ERROR, "mu_stream_ioctl", NULL, rc);
+      return rc;
+    }
+  
+  *nflt = 0;
+  fd = (int) (intptr_t) trans[0];
+  if (fstat (fd, &st) == 0)
+    {
+      switch (st.st_mode & S_IFMT)
+        {
+        case S_IFREG:
+          return 0;
+
+        case S_IFCHR:
+          flt[(*nflt)++] = "7BIT";
+#if defined(OPOST) && defined(ONLCR)
+          {
+            struct termios tbuf;
+        
+            if (!(tcgetattr (fd, &tbuf) == 0
+                  && (tbuf.c_oflag & OPOST) && (tbuf.c_oflag & ONLCR)))
+              {
+                flt[(*nflt)++] = "+";
+                flt[(*nflt)++] = "CRLF";
+              }
+          }
 #else
-  return 1; /* Just in case */
+          /* Just in case */
+          flt[(*nflt)++] = "+";
+          flt[(*nflt)++] = "CRLF";
 #endif
+          break;
+
+        case S_IFSOCK:
+          return 0;
+
+        default:
+          /* FIXME: Perhaps an error? */
+          return 0;
+        }
+    }
+
+  return 0;
 }
 
 static mu_stream_t
 _open_tty (const char *device, int argc, char **argv)
 {
-  mu_stream_t dev, base_dev, prev_stream;
+  mu_stream_t dev;
   int status;
+  char *dfl_argv[4];
   
-  status = mu_file_stream_create (&dev, device, MU_STREAM_WRITE);
+  status = mu_file_stream_create (&dev, device, MU_STREAM_APPEND|MU_STREAM_CREAT);
   if (status)
     {
       mu_error (_("cannot open device %s: %s"),
                 device, mu_strerror (status));
       return NULL;
     }
   mu_stream_set_buffer (dev, mu_buffer_line, 0);
 
-  prev_stream = base_dev = dev;
-  while (argc)
+  if (argc == 0)
     {
-      int i;
-      int mode;
-      int qmark;
-      char *fltname;
-      
-      fltname = argv[0];
-      if (fltname[0] == '?')
-        {
-          qmark = 1;
-          fltname++;
-        }
-      else
-        qmark = 0;
-      
-      if (fltname[0] == '~')
-        {
-          mode = MU_FILTER_DECODE;
-          fltname++;
-        }
-      else
-        {
-          mode = MU_FILTER_ENCODE;
-        }
-      
-      for (i = 1; i < argc; i++)
-        if (strcmp (argv[i], "+") == 0)
-          break;
-      
-      if (qmark == 0 || need_crlf (base_dev))
-        {
-          status = mu_filter_create_args (&dev, prev_stream, fltname,
-                                          i, (const char **)argv,
-                                          mode, MU_STREAM_WRITE);
-          mu_stream_unref (prev_stream);
-          if (status)
-            {
-              mu_error (_("cannot open filter stream: %s"),
-                        mu_strerror (status));
+      status = study_tty (dev, dfl_argv, &argc);
+      if (status)
+        return NULL;
+      argv = dfl_argv;
+    }
+
+  if (argc)
+    {
+      mu_stream_t str;
+      status = mu_filter_chain_create (&str, dev,
+                                       MU_FILTER_ENCODE, MU_STREAM_WRITE,
+                                       argc, argv);
+      mu_stream_unref (dev);
+      if (status)