Fix serial i/o on Windows.

Fix bytes read count accumulation in Windows serial I/O.

read_string  from  communications  port   doesn't  handle  timeout  on
anything but the first character read.

Honour VMIN tty parameter correctly.

lib/termios.c

@@ -1387,11 +1387,15 @@ int win32_serial_read( int fd, void *vb, int size )
 	if ( index->open_flags & O_NONBLOCK  )
     {
       /* pull mucho-cpu here? */
-		do {
+      do
+        {
 #ifdef DEBUG_VERBOSE
           report( "vmin=0\n" );
 #endif /* DEBUG_VERBOSE */
           ClearErrors( index, &stat);
+
+          if (stat.cbInQue < index->ttyset->c_cc[VMIN])
+            {
               /*
                 usleep(1000);
                 usleep(50);
@@ -1399,14 +1403,16 @@ int win32_serial_read( int fd, void *vb, int size )
               /* we should use -1 instead of 0 for disabled timeout */
               now = GetTickCount();
               if (index->ttyset->c_cc[VTIME] &&
-				now-start >= (index->ttyset->c_cc[VTIME]*100)) {
+                  now-start >= (index->ttyset->c_cc[VTIME]*100))
+                {
                   /*
                     sprintf( message, "now = %i start = %i time = %i total =%i\n", now, start, index->ttyset->c_cc[VTIME]*100, total);
                     report( message );
                   */
                   return total;	/* read timeout */
                 }
-		} while( stat.cbInQue < size && size > 1 );
+            }
+        } while (size > 1 && stat.cbInQue < index->ttyset->c_cc[VMIN]);
     }
   else
     {
@@ -1421,7 +1427,7 @@ int win32_serial_read( int fd, void *vb, int size )
 		do {
 			ClearErrors( index, &stat);
 			usleep(1000);
-		} while ( c > clock() );
+    } while (stat.cbInQue < index->ttyset->c_cc[VMIN] && c > clock());
 
 	}
 
@@ -1441,8 +1447,6 @@ int win32_serial_read( int fd, void *vb, int size )
                 ( int ) nBytes, (char *) dest + total );
         report( message );
 #endif /* DEBUG_VERBOSE */
-		size -= nBytes;
-		total += nBytes;
 
         if ( !err )
           {
@@ -1505,6 +1509,9 @@ int win32_serial_read( int fd, void *vb, int size )
           }
         else
           {
+            size -= nBytes;
+            total += nBytes;
+
             /*
               usleep(1000);
             */
@@ -1614,8 +1621,6 @@ int win32_serial_read( int fd, void *vb, int size )
 			( int ) nBytes, (char *) dest + total );
 		report( message );
 #endif /* DEBUG_VERBOSE */
-		size -= nBytes;
-		total += nBytes;
 
 		if ( !err )
 		{
@@ -1682,6 +1687,9 @@ int win32_serial_read( int fd, void *vb, int size )
 		}
 		else
 		{
+      size -= nBytes;
+      total += nBytes;
+
 /*
 			usleep(1000);
 */

src/iofunc.c

@@ -504,8 +504,17 @@ int HAMLIB_API read_string(hamlib_port_t *p, char *rxbuffer, size_t rxmax, const
 	efds = rfds;
 
 	retval = port_select(p, p->fd+1, &rfds, NULL, &efds, &tv);
-        if (retval == 0)    /* Timed out */
+	if (retval == 0) {
-            break;
+		/* Record timeout time and caculate elapsed time */
+		gettimeofday(&end_time, NULL);
+		timersub(&end_time, &start_time, &elapsed_time);
+
+		dump_hex((unsigned char *) rxbuffer, total_count);
+		rig_debug(RIG_DEBUG_WARN, "%s(): Timed out %d.%d seconds after %d chars\n",
+			  __func__, elapsed_time.tv_sec, elapsed_time.tv_usec, total_count);
+
+		return -RIG_ETIMEOUT;
+	}
 
 	if (retval < 0) {
 		dump_hex((unsigned char *) rxbuffer, total_count);
@@ -543,17 +552,6 @@ int HAMLIB_API read_string(hamlib_port_t *p, char *rxbuffer, size_t rxmax, const
    */
   rxbuffer[total_count] = '\000';
 
-  if (total_count == 0) {
-    /* Record timeout time and caculate elapsed time */
-    gettimeofday(&end_time, NULL);
-    timersub(&end_time, &start_time, &elapsed_time);
-
-    rig_debug(RIG_DEBUG_WARN, "%s(): Timed out %d.%d seconds without reading a character.\n",
-	      __func__, elapsed_time.tv_sec, elapsed_time.tv_usec);
-
-    return -RIG_ETIMEOUT;
-  }
-
   rig_debug(RIG_DEBUG_TRACE,"%s(): RX %d characters\n", __func__, total_count);
   dump_hex((unsigned char *) rxbuffer, total_count);