relayd: silence null dereference warning during viewer stream creation

Coverity warns that the vstream's trace chunk may be used NULL.
However, this won't happen if the corresponding relay stream has
an active trace chunk.

Coverity report:
  1433620 Dereference after null check

  Either the check against null is unnecessary, or there may be a
  null pointer dereference.

  In viewer_stream_create: Pointer is checked against null but then
  dereferenced anyway (CWE-476)

Reported-by: Coverity Scan
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: Ie032ed415a99cfff149e3325d05f37ededb52d33

diff --git a/src/bin/lttng-relayd/viewer-stream.c b/src/bin/lttng-relayd/viewer-stream.c
index 67c452eec7d4264139f1134b1fcdd4bc2aa2d49c..00616569ba0b147e7ce63181bcf82e21e84596c1 100644 (file)
--- a/src/bin/lttng-relayd/viewer-stream.c
+++ b/src/bin/lttng-relayd/viewer-stream.c
@@ -122,7 +122,7 @@ struct relay_viewer_stream *viewer_stream_create(struct relay_stream *stream,
         */
        if (stream->index_file == NULL) {
                vstream->index_file = NULL;
-       } else {
+       } else if (vstream->stream_file.trace_chunk) {
                const uint32_t connection_major = stream->trace->session->major;
                const uint32_t connection_minor = stream->trace->session->minor;
                enum lttng_trace_chunk_status chunk_status;
@@ -150,7 +150,7 @@ struct relay_viewer_stream *viewer_stream_create(struct relay_stream *stream,
         * If we never received a data file for the current stream, delay the
         * opening, otherwise open it right now.
         */
-       if (stream->file) {
+       if (stream->file && vstream->stream_file.trace_chunk) {
                int ret;
                char file_path[LTTNG_PATH_MAX];
                enum lttng_trace_chunk_status status;