From: Francis Deslauriers <francis.deslauriers@efficios.com>
Date: Fri, 9 Aug 2019 20:35:54 +0000 (-0400)
Subject: Fix: flt.utils.muxer: Explicit null dereferenced
X-Git-Url: http://git.efficios.com/?a=commitdiff_plain;h=e5b2784a600fc88369f51d73666bcf56f83ce33f;p=babeltrace.git

Fix: flt.utils.muxer: Explicit null dereferenced

Fixes coverity #1404006

  ID 1404006 (#1 of 1): Explicit null dereferenced (FORWARD_NULL)
  18. var_deref_op: Dereferencing null pointer *muxer_upstream_msg_iter

Signed-off-by: Francis Deslauriers <francis.deslauriers@efficios.com>
Change-Id: I055200226ab13653b219a084f38a2dd9bb16664b
Reviewed-on: https://review.lttng.org/c/babeltrace/+/1859
CI-Build: Philippe Proulx <eeppeliteloop@gmail.com>
Tested-by: jenkins <jenkins@lttng.org>
Reviewed-by: Philippe Proulx <eeppeliteloop@gmail.com>
---

diff --git a/src/plugins/utils/muxer/muxer.c b/src/plugins/utils/muxer/muxer.c
index ecd5d8d9..f67955d1 100644
--- a/src/plugins/utils/muxer/muxer.c
+++ b/src/plugins/utils/muxer/muxer.c
@@ -946,7 +946,13 @@ muxer_msg_iter_youngest_upstream_msg_iter(
 			goto end;
 		}
 
-		if (msg_ts_ns < youngest_ts_ns) {
+		/*
+		 * Update the current message iterator if it has not been set
+		 * yet, or if its current message has a timestamp smaller than
+		 * the previously selected youngest message.
+		 */
+		if (G_UNLIKELY(*muxer_upstream_msg_iter == NULL) ||
+				msg_ts_ns < youngest_ts_ns) {
 			*muxer_upstream_msg_iter =
 				cur_muxer_upstream_msg_iter;
 			youngest_ts_ns = msg_ts_ns;