From 9b964db4c915bc91a7b2fb113bc8b68f8073bee4 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Sebastian=20Dr=C3=B6ge?= <sebastian@centricular.com>
Date: Mon, 5 Dec 2022 12:15:55 +0200
Subject: [PATCH] whipsink: Handle offer creation errors more gracefully

Part-of: <https://gitlab.freedesktop.org/gstreamer/gst-plugins-rs/-/merge_requests/949>
---
 net/webrtchttp/src/whepsrc/imp.rs  |  2 +-
 net/webrtchttp/src/whipsink/imp.rs | 25 ++++++++++++++++++++-----
 2 files changed, 21 insertions(+), 6 deletions(-)

diff --git a/net/webrtchttp/src/whepsrc/imp.rs b/net/webrtchttp/src/whepsrc/imp.rs
index 5b38ef1f..74e8ee75 100644
--- a/net/webrtchttp/src/whepsrc/imp.rs
+++ b/net/webrtchttp/src/whepsrc/imp.rs
@@ -845,7 +845,7 @@ impl WhepSrc {
                 gst::element_imp_error!(
                     self_,
                     gst::LibraryError::Failed,
-                    ["generate offer::Promise returned with no reply: {}", error]
+                    ["generate offer::Promise returned with error: {}", error]
                 );
             }
         });
diff --git a/net/webrtchttp/src/whipsink/imp.rs b/net/webrtchttp/src/whipsink/imp.rs
index 12ef0dee..9739e92c 100644
--- a/net/webrtchttp/src/whipsink/imp.rs
+++ b/net/webrtchttp/src/whipsink/imp.rs
@@ -427,11 +427,26 @@ impl ObjectImpl for WhipSink {
                     let whipsink = ele.imp();
 
                     let offer_sdp = match reply {
-                        Ok(Some(sdp)) => sdp
-                            .value("offer")
-                            .expect("structure must have an offer key")
-                            .get::<gst_webrtc::WebRTCSessionDescription>()
-                            .expect("offer must be an SDP"),
+                        Ok(Some(reply)) => {
+                            if let Ok(sdp) = reply.value("offer").map(|offer| {
+                                offer.get::<gst_webrtc::WebRTCSessionDescription>().unwrap()
+                            }) {
+                                sdp
+                            } else {
+                                let error = reply
+                                    .value("error")
+                                    .expect("structure must have an error value")
+                                    .get::<glib::Error>()
+                                    .expect("value must be a GLib error");
+
+                                gst::element_imp_error!(
+                                    whipsink,
+                                    gst::LibraryError::Failed,
+                                    ["generate offer::Promise returned with error: {}", error]
+                                );
+                                return;
+                            }
+                        }
                         Ok(None) => {
                             gst::element_error!(
                                 ele,