[Spice-devel] [PATCH spice-server] red-stream: Handle reading of 0 bytes in red_stream_async_read

[Frediano Ziglio]

Currently red_stream_async_read cannot handle read of 0 bytes.
This would cause a wrong assert in async_read_handler.
Fixing the assert would just make the code wrongly detect a
disconnection (usually a return of 0 from read is handled that
way but happens also if you try to read 0 bytes).
Current callers of these function does not pass 0 as size however
handling data protocols having data_length+data this can happen
and is handled manually in red_sasl_handle_auth_steplen.
Avoid needing manually to check for this condition.

Signed-off-by: Frediano Ziglio <fziglio at redhat.com>
---
 server/red-stream.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/server/red-stream.c b/server/red-stream.c
index 8f2c9d32..bdc8bc1f 100644
--- a/server/red-stream.c
+++ b/server/red-stream.c
@@ -550,6 +550,10 @@ void red_stream_async_read(RedStream *stream,
     AsyncRead *async = &stream->priv->async_read;
 
     g_return_if_fail(async->now == NULL && async->end == NULL);
+    if (size == 0) {
+        read_done_cb(opaque);
+        return;
+    }
     async->now = data;
     async->end = async->now + size;
     async->done = read_done_cb;
@@ -904,10 +908,6 @@ static void red_sasl_handle_auth_steplen(void *opaque)
         return red_sasl_async_result(opaque, auth->mechname ? RED_SASL_ERROR_INVALID_DATA : RED_SASL_ERROR_GENERIC);
     }
 
-    if (len == 0) {
-        return red_sasl_handle_auth_step(auth);
-    }
-
     auth->data = g_realloc(auth->data, len);
     red_stream_async_read(auth->stream, (uint8_t *)auth->data, len,
                           red_sasl_handle_auth_step, auth);
-- 
2.14.3