Bugfixes in stream-related code.

* mailbox/fltstream.c (filter_read): Do not try to get more input until
the output buffer is drained.
* mailbox/mapfile_stream.c (_mapfile_seek): Fix conditional.
* mailbox/stream.c (_stream_fill_buffer): Fix increment.
(mu_stream_skip_input_bytes): Bugfixes.

@@ -117,9 +117,12 @@ filter_read (mu_stream_t stream, char *buf, size_t size, size_t *pret)
   
   while (total < size && cmd != mu_filter_lastbuf)
     {
+      size_t rdsize;
+
+      if (MFB_RDBYTES (fs->outbuf) == 0)
+	{
 	  enum mu_filter_result res;
 	  int rc;
-      size_t rdsize;
 	  
 	  if (MFB_RDBYTES (fs->inbuf) < min_input_level)
 	    {
@@ -133,7 +136,8 @@ filter_read (mu_stream_t stream, char *buf, size_t size, size_t *pret)
 	      if (rc)
 		return rc;
 	      if (rdsize == 0 &&
-	      MFB_RDBYTES (fs->outbuf) == 0 && MFB_RDBYTES (fs->inbuf) == 0)
+		  MFB_RDBYTES (fs->outbuf) == 0
+		  && MFB_RDBYTES (fs->inbuf) == 0)
 		break;
 	      MFB_advance_level (&fs->inbuf, rdsize);
 	    }
@@ -183,6 +187,7 @@ filter_read (mu_stream_t stream, char *buf, size_t size, size_t *pret)
 	  
 	  /* iobuf.isize contains number of bytes read from input */
 	  MFB_advance_pos (&fs->inbuf, iobuf.isize);
+	}
 
       rdsize = size - total;
       if (rdsize > MFB_RDBYTES (fs->outbuf))

@@ -316,7 +316,7 @@ _mapfile_seek (struct _mu_stream *str, mu_off_t off, mu_off_t *presult)
 { 
   struct _mu_mapfile_stream *mfs = (struct _mu_mapfile_stream *) str;
   
-  if (off < 0 || off >= mfs->size)
+  if (off < 0 || off > mfs->size)
     return ESPIPE;
   mfs->offset = off;
   *presult = off;

@@ -80,9 +80,9 @@ _stream_fill_buffer (struct _mu_stream *stream)
 	   n < stream->bufsize
 	     && (rc = mu_stream_read_unbuffered (stream,
 						 &c, 1, 0, &rdn)) == 0
-	     && rdn; n++)
+	     && rdn; )
 	{
-	  stream->buffer[n] = c;
+	  stream->buffer[n++] = c;
 	  if (c == '\n')
 	    break;
 	}
@@ -368,10 +368,10 @@ mu_stream_skip_input_bytes (mu_stream_t stream, mu_off_t count, mu_off_t *pres)
     }
   else
     {
-      if ((rc = _stream_flush_buffer (stream, 1)))
-	return rc;
       for (pos = 0;;)
 	{
+	  if ((rc = _stream_flush_buffer (stream, 1)))
+	    return rc;
 	  if (stream->level == 0)
 	    {
 	      rc = _stream_fill_buffer (stream);
@@ -385,11 +385,13 @@ mu_stream_skip_input_bytes (mu_stream_t stream, mu_off_t count, mu_off_t *pres)
 	    }
 	  if (pos <= count && count < pos + stream->level)
 	    {
-	      rc = 0;
-	      stream->cur = stream->buffer + count - pos;
+	      size_t delta = count - pos;
+	      _stream_advance_buffer (stream, delta);
 	      pos = count;
+	      rc = 0;
 	      break;
 	    }
+	  pos += stream->level;
 	}
     }