Index: cygwin/fhandler_serial.cc
===================================================================
RCS file: /cvs/src/src/winsup/cygwin/fhandler_serial.cc,v
retrieving revision 1.40
diff -u -p -r1.40 fhandler_serial.cc
--- cygwin/fhandler_serial.cc	10 Jan 2003 12:32:46 -0000	1.40
+++ cygwin/fhandler_serial.cc	23 Jan 2003 00:07:32 -0000
@@ -530,8 +530,8 @@ fhandler_serial::tcsetattr (int action, 
   COMMTIMEOUTS to;
   DCB ostate, state;
   unsigned int ovtime = vtime_, ovmin = vmin_;
-  int tmpDtr, tmpRts;
-  tmpDtr = tmpRts = 0;
+  int tmpDtr, tmpRts, setcommerr;
+  setcommerr = tmpDtr = tmpRts = 0;
 
   termios_printf ("action %d", action);
   if ((action == TCSADRAIN) || (action == TCSAFLUSH))
@@ -554,9 +554,10 @@ fhandler_serial::tcsetattr (int action, 
 
   switch (t->c_ospeed)
     {
-      case B0:	/* drop DTR */
+      case B0:
+    /* Drop DTR - but leave DCB-resident bitrate as-is since
+       0 is an invalid bitrate in Win32 */
 	dropDTR = TRUE;
-	state.BaudRate = 0;
 	break;
       case B110:
 	state.BaudRate = CBR_110;
@@ -725,8 +726,16 @@ fhandler_serial::tcsetattr (int action, 
 
   state.fAbortOnError = TRUE;
 
-  if (memcmp (&ostate, &state, sizeof (state)) != 0)
-    SetCommState (get_handle (), &state);
+  if ((memcmp (&ostate, &state, sizeof (state)) != 0) &&
+      !SetCommState (get_handle (), &state))
+  {
+    /* SetCommState() failed, usually due to invalid DCB param.
+       Keep track of this so we can set errno to EINVAL later
+       and return failure */
+    termios_printf ("SetCommState() failed, GetLastError = %d",
+                    GetLastError());
+    setcommerr = -1;
+  }
 
   set_r_binary ((t->c_iflag & IGNCR) ? 0 : 1);
   set_w_binary ((t->c_oflag & ONLCR) ? 0 : 1);
@@ -794,49 +803,55 @@ fhandler_serial::tcsetattr (int action, 
 
   debug_printf ("vtime %d, vmin %d", vtime_, vmin_);
 
-  if (ovmin == vmin_ && ovtime == vtime_)
-    return 0;
+  if (ovmin != vmin_ || ovtime != vtime_)
+  {
+    memset (&to, 0, sizeof (to));
 
-  memset (&to, 0, sizeof (to));
-
-  if ((vmin_ > 0) && (vtime_ == 0))
+    if ((vmin_ > 0) && (vtime_ == 0))
     {
       /* Returns immediately with whatever is in buffer on a ReadFile();
-	 or blocks if nothing found.  We will keep calling ReadFile(); until
-	 vmin_ characters are read */
+         or blocks if nothing found.  We will keep calling ReadFile(); until
+         vmin_ characters are read */
       to.ReadIntervalTimeout = to.ReadTotalTimeoutMultiplier = MAXDWORD;
       to.ReadTotalTimeoutConstant = MAXDWORD - 1;
     }
-  else if ((vmin_ == 0) && (vtime_ > 0))
+    else if ((vmin_ == 0) && (vtime_ > 0))
     {
       /* set timeoout constant appropriately and we will only try to
-	 read one character in ReadFile() */
+         read one character in ReadFile() */
       to.ReadTotalTimeoutConstant = vtime_;
       to.ReadIntervalTimeout = to.ReadTotalTimeoutMultiplier = MAXDWORD;
     }
-  else if ((vmin_ > 0) && (vtime_ > 0))
+    else if ((vmin_ > 0) && (vtime_ > 0))
     {
       /* time applies to the interval time for this case */
       to.ReadIntervalTimeout = vtime_;
     }
-  else if ((vmin_ == 0) && (vtime_ == 0))
+    else if ((vmin_ == 0) && (vtime_ == 0))
     {
       /* returns immediately with whatever is in buffer as per
-	 Time-Outs docs in Win32 SDK API docs */
+         Time-Outs docs in Win32 SDK API docs */
       to.ReadIntervalTimeout = MAXDWORD;
     }
 
-  debug_printf ("ReadTotalTimeoutConstant %d, ReadIntervalTimeout %d, ReadTotalTimeoutMultiplier %d",
-		to.ReadTotalTimeoutConstant, to.ReadIntervalTimeout, to.ReadTotalTimeoutMultiplier);
-  int res = SetCommTimeouts (get_handle (), &to);
-  if (!res)
-    {
-      system_printf ("SetCommTimeout failed, %E");
-      __seterrno ();
-      return -1;
-    }
+    debug_printf ("ReadTotalTimeoutConstant %d, ReadIntervalTimeout %d, ReadTotalTimeoutMultiplier %d",
+                  to.ReadTotalTimeoutConstant, to.ReadIntervalTimeout, to.ReadTotalTimeoutMultiplier);
 
-  return 0;
+    if (!SetCommTimeouts(get_handle (), &to))
+    {
+      /* SetCommTimeouts() failed. Keep track of this so we
+         can set errno to EINVAL later and return failure */
+      termios_printf ("SetCommTimeouts() failed, GetLastError = %d",
+                      GetLastError());
+      setcommerr = -1;
+    }
+  }
+
+  /* If one or more of the Win32 SetComm*()'s failed,
+     set errno = EINVAL */
+  if (setcommerr) set_errno(EINVAL);
+  
+  return setcommerr;
 }
 
 /* tcgetattr: POSIX 7.2.1.1 */
@@ -854,12 +869,10 @@ fhandler_serial::tcgetattr (struct termi
 
   /* -------------- Baud rate ------------------ */
 
-  switch (state.BaudRate)
+  /* If DTR is NOT set, return B0 as our speed */
+  if (dtr != TIOCM_DTR) t->c_cflag = t->c_ospeed = t->c_ispeed = B0;
+  else switch (state.BaudRate)
     {
-      case 0:
-	/* FIXME: need to drop DTR */
-	t->c_cflag = t->c_ospeed = t->c_ispeed = B0;
-	break;
       case CBR_110:
 	t->c_cflag = t->c_ospeed = t->c_ispeed = B110;
 	break;