From 096987a31cfdecd74b6e49ede5a4331e3d16fc51 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Fran=C3=A7ois=20Laignel?= <francois@centricular.com>
Date: Wed, 2 Jul 2025 13:33:34 +0200
Subject: [PATCH] rtpbin2: sync: fix race condition

Under some circumstances, the `ssrc` could be added to the `ssrcs` map without
the `clock_rate` being defined. When `rtprecv` would check wether the ssrc
`has_clock_rate()`, it would return `true` spuriously, which would then cause a
panic in `calculate_pts()`.

Part-of: <https://gitlab.freedesktop.org/gstreamer/gst-plugins-rs/-/merge_requests/2337>
---
 net/rtp/src/rtpbin2/sync.rs | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/net/rtp/src/rtpbin2/sync.rs b/net/rtp/src/rtpbin2/sync.rs
index 2b62341b4..5f41031f9 100644
--- a/net/rtp/src/rtpbin2/sync.rs
+++ b/net/rtp/src/rtpbin2/sync.rs
@@ -119,7 +119,9 @@ impl Context {
     }
 
     pub fn has_clock_rate(&self, ssrc_val: u32) -> bool {
-        self.ssrcs.contains_key(&ssrc_val)
+        self.ssrcs
+            .get(&ssrc_val)
+            .is_some_and(|ssrc| ssrc.clock_rate.is_some())
     }
 
     fn disassociate(&mut self, ssrc_val: u32, cname: &str) {