Fix crash when selecing Pro Audio profile.

src/backend/pwnodeobject.rs

@@ -613,9 +613,9 @@ impl PwNodeObject {
     }
 
 
-    pub(crate) fn node_property<T: FromPipewirePropertyString>(&self, property: &str) -> T {
+    pub(crate) fn node_property<T: FromPipewirePropertyString>(&self, property: &str) -> Option<T> {
         let node = self.imp().wpnode.get().expect("node");
-        node.pw_property(property).expect(property)
+        node.pw_property(property).ok()
     }
 }
 

src/ui/sinkbox.rs

@@ -88,7 +88,7 @@ mod imp {
             let parent: &PwVolumeBox = obj.upcast_ref();
             let node = parent.node_object().expect("nodeobj");
             let node_name: String = if _togglebutton.is_active() {
-                node.node_property("node.name")
+                node.node_property("node.name").unwrap_or_default()
             } else {
                 "".to_string()
             };

src/ui/volumebox.rs

@@ -10,6 +10,8 @@ use std::cell::{Cell, RefCell, OnceCell};
 use wireplumber as wp;
 
 mod imp {
+    use crate::pwvucontrol_warning;
+
     use super::*;
 
     #[derive(Default, gtk::CompositeTemplate, glib::Properties)]
@@ -125,7 +127,11 @@ mod imp {
             let defaultnodesapi = manager.default_nodes_api();
             let widget = self.obj();
             let defaultnodesapi_closure = closure_local!(@watch widget, @strong item => move |defaultnodesapi: wp::plugin::Plugin| {
-                let media_class: String = item.node_property("media.class");
+                let Some(media_class) = item.node_property::<String>("media.class")
+                else {
+                    pwvucontrol_warning!("{} is missing media.class property", item.name());
+                    return;
+                };
                 let id: u32 = defaultnodesapi.emit_by_name("get-default-node", &[&media_class]);
                 wp::info!("default-nodes-api changed: new id {id}");
                 widget.imp().default_node.set(id);