fix(mirror): install gtksink on Arch; cancel stale video receivers

linux/packaging/install-deps.sh

@@ -92,7 +92,12 @@ case "$PM" in
     BUILD=(base-devel pkgconf curl
            webkit2gtk-4.1 gtk3 libayatana-appindicator librsvg
            dbus openssl protobuf gst-plugins-base-libs)
+    # gst-plugin-gtk carries `gtksink`, which the screen-mirror pipeline ends in
+    # (see ui-tauri mirror.rs). Arch split it OUT of gst-plugins-good, so
+    # installing the latter is not enough — without this the mirror window opens
+    # and spins forever on "gst parse: no element gtksink".
     RUN=(gst-plugins-base gst-plugins-good gst-plugins-bad gst-libav
+         gst-plugin-gtk
          libpulse networkmanager zenity android-tools
          nautilus-python python-pillow)
     NODE_PKGS=(nodejs npm)
@@ -159,6 +164,30 @@ set -e
 [ "$PM_RC" -eq 0 ] && ok "System packages installed." \
                    || warn "Package manager exited $PM_RC — some names may differ on your distro; check the log above."
 
+# ── verify gtksink ────────────────────────────────────────────────────────────
+# The screen-mirror / second-screen / continuity-camera pipelines all end in
+# `gtksink`. Which package ships it varies (Arch splits it out of
+# gst-plugins-good entirely), and when it's absent the failure is invisible:
+# the mirror window opens, spins on "Connecting…" forever, and the real reason
+# ("gst parse: no element gtksink") only appears in the log. Check it here
+# instead of shipping a guess for every distro.
+if command -v gst-inspect-1.0 >/dev/null 2>&1; then
+  if gst-inspect-1.0 gtksink >/dev/null 2>&1; then
+    ok "GStreamer gtksink present (screen mirroring can render)."
+  else
+    warn "GStreamer 'gtksink' is MISSING — the screen features will open a window that never shows a picture."
+    case "$PM" in
+      pacman)  warn "  Install it with: sudo pacman -S --needed gst-plugin-gtk" ;;
+      apt-get) warn "  Try: sudo apt-get install gstreamer1.0-gtk3" ;;
+      dnf)     warn "  Try: sudo dnf install gstreamer1-plugins-good-gtk" ;;
+      *)       warn "  Install your distro's GStreamer GTK sink plugin (provides libgstgtk.so)." ;;
+    esac
+    warn "  Everything else (notifications, clipboard, calls, files) works without it."
+  fi
+else
+  warn "gst-inspect-1.0 not found — cannot verify 'gtksink'; screen mirroring may not render."
+fi
+
 # ── Node + npm (separate & conditional) ───────────────────────────────────────
 # Only touch node when it's genuinely missing — if a working node+npm already
 # exists (NodeSource, nvm, distro, …) we leave it alone, which is exactly what

linux/ui-tauri/src-tauri/src/mirror.rs

@@ -33,6 +33,40 @@ use vortex_l3_daemon::core::{mirror_tcp, mirror_udp};
 /// loop pushes into `input_tx`; `stop_mirror` takes + closes it.
 static MIRROR_HANDLE: std::sync::Mutex<Option<MirrorHandle>> = std::sync::Mutex::new(None);
 
+/// The live TCP video receiver task. Held so it can be ABORTED on teardown.
+///
+/// Without this it outlives its session: the receiver retries the connect for
+/// as long as the phone's video server is closed (it only opens after the user
+/// taps "Start now" on the consent dialog), so a second Start — a double click,
+/// or the address-retry pass — leaves the first receiver still looping. Both
+/// then connect the instant the phone's server opens, each holding a media key
+/// derived from its OWN session's IK handshake hash. The phone encrypts for the
+/// session it honoured (it debounces the duplicate START, see Android
+/// `VortexStack.kt`), so the other receiver fails to open frame 0
+/// ("AEAD open failed counter=0"), closes the socket, and takes the whole
+/// stream down with it — leaving the window spinning on a mirror that had in
+/// fact connected.
+static VIDEO_RX_TASK: std::sync::Mutex<Option<tokio::task::JoinHandle<()>>> =
+    std::sync::Mutex::new(None);
+
+/// Abort any previous video receiver and remember the new one.
+fn set_video_rx_task(task: tokio::task::JoinHandle<()>) {
+    if let Ok(mut g) = VIDEO_RX_TASK.lock() {
+        if let Some(prev) = g.take() {
+            prev.abort();
+        }
+        *g = Some(task);
+    }
+}
+
+/// Abort the live video receiver, if any.
+fn abort_video_rx_task() {
+    let prev = VIDEO_RX_TASK.lock().ok().and_then(|mut g| g.take());
+    if let Some(t) = prev {
+        t.abort();
+    }
+}
+
 /// The live GStreamer pipeline. Held so a UI "Stop sharing" (and `cleanup`) can
 /// set it to Null without relying on the bus EOS cascade. It must reach Null
 /// BEFORE the mirror window goes away — the sink is drawing into that window.
@@ -881,12 +915,14 @@ pub async fn spawn_mirror(
     // needed (the laptop is the connecting side; its firewall allows that).
     let key = mirror_udp::derive_media_key(&handle.handshake_hash);
     let (au_tx, au_rx) = mpsc::channel::<Vec<u8>>(8);
-    tokio::spawn(mirror_tcp::run_tcp_video_receiver(
+    // Tracked + cancellable: a receiver from a previous session would otherwise
+    // still be retrying its connect with a stale media key. See VIDEO_RX_TASK.
+    set_video_rx_task(tokio::spawn(mirror_tcp::run_tcp_video_receiver(
         phone_addr.ip(),
         key,
         au_tx,
         Some(handle.keyframe_tx.clone()),
-    ));
+    )));
 
     let backend = detect_decoder_backend();
     start_player(app, backend, width, height, au_rx);
@@ -922,6 +958,9 @@ pub async fn stop_mirror() {
     }
     POINTER_DOWN.store(false, Ordering::Relaxed);
     SCROLL_ACTIVE.store(false, Ordering::Relaxed);
+    // Kill the video receiver before the decoder: it must not outlive this
+    // session and reconnect later with a now-stale media key.
+    abort_video_rx_task();
     // Decoder first, then the window it renders into.
     stop_pipeline();
     crate::mirror_window::close();