2001-01-20 Roland McGrath <roland@frob.com>

	* streamio.c (options): Add aliases --rdonly, --ro for -r.
	Add aliases --rdwr, -rw for -w.
	Add new option --writeonly/--wronly/-W.
	(readonly): Variable removed.
	(parse_opt): Set trivfs_allow_open for -r/-w/-W.
	(main): Don't set trivfs_allow_open here.  Instead, use it to decide
	whether to set up input_buffer/output_buffer or not.
	(open_hook): Use trivfs_allow_open instead of readonly.
	Check whether read is allowed too.
	(trivfs_modify_stat): Likewise.
	(clear_buffer): Do nothing if argument is null.
	* streamio.c (stream_name, readonly, rdev, nperopens): Remove
	superfluous zero initializers.

1 files changed, 2 insertions, 0 deletions

diff --git a/trans/streamio.c b/trans/streamio.c
index 13714239..c1acc8a2 100644
--- a/trans/streamio.c
+++ b/trans/streamio.c
@@ -104,6 +104,8 @@ buffer_writable (struct buffer *b)
 extern inline void
 clear_buffer (struct buffer *b)
 {
+  if (b == 0)
+    return;
   b->head = b->tail = b->buf;
   condition_broadcast (b->wait);
 }