🐛 zx: Fix declaring proxies for writable properties

The `#[dbus_proxy(property)]` attribute needs to be present also at the
`set_foo` function, otherwise the proxy will call a `SetFoo` method instead of
`Set`ting the `Foo` property.

Example:
agama-project/agama#712

zbus_xmlgen/src/lib.rs

@@ -65,21 +65,22 @@ impl<'i> Display for GenTrait<'i> {
         props.sort_by(|a, b| a.name().partial_cmp(&b.name()).unwrap());
         for p in props {
             let name = to_identifier(&to_snakecase(p.name().as_str()));
+            let fn_attribute = if pascal_case(&name) != p.name().as_str() {
+                format!("    #[dbus_proxy(property, name = \"{}\")]", p.name())
+            } else {
+                "    #[dbus_proxy(property)]".to_string()
+            };
 
             writeln!(f)?;
             writeln!(f, "    /// {} property", p.name())?;
-            if pascal_case(&name) != p.name().as_str() {
-                writeln!(f, "    #[dbus_proxy(property, name = \"{}\")]", p.name())?;
-            } else {
-                writeln!(f, "    #[dbus_proxy(property)]")?;
-            }
-
             if p.access().read() {
+                writeln!(f, "{}", fn_attribute)?;
                 let output = to_rust_type(p.ty(), false, false);
                 writeln!(f, "    fn {name}(&self) -> zbus::Result<{output}>;",)?;
             }
 
             if p.access().write() {
+                writeln!(f, "{}", fn_attribute)?;
                 let input = to_rust_type(p.ty(), true, true);
                 writeln!(
                     f,

zbus_xmlgen/tests/data/sample_object0.rs

@@ -21,5 +21,6 @@ trait SampleInterface0 {
     /// Bar property
     #[dbus_proxy(property)]
     fn bar(&self) -> zbus::Result<u8>;
+    #[dbus_proxy(property)]
     fn set_bar(&self, value: u8) -> zbus::Result<()>;
 }