fix(#442): merge saved connection patches before update

nmrs/CHANGELOG.md

@@ -7,6 +7,9 @@ All notable changes to the `nmrs` crate will be documented in this file.
 - `NetworkManager::get_saved_connection_uuid()` — resolve a profile UUID from `connection.id` (usually the Wi-Fi SSID) for use with `update_saved_connection` ([#442](https://github.com/networkmanager-rs/nmrs/issues/442))
 - `DeviceState::is_enabled()`, `Device.frequency`, and `WifiDevice.active_frequency_mhz` expose device usability and active Wi-Fi AP frequency without requiring separate AP lookups ([#445](https://github.com/networkmanager-rs/nmrs/pull/445))
 
+### Fixed
+- `NetworkManager::update_saved_connection()` now merges `SettingsPatch` into the full existing settings map before calling NetworkManager `Update`, avoiding missing required fields such as `connection.type` ([#446](https://github.com/networkmanager-rs/nmrs/pull/446))
+
 ## [3.2.0] - 2026-05-31
 ### Added
 - Add EAP-TLS support for WPA-Enterprise Wi-Fi, including TLS certificate/key path or blob configuration on `EapOptions` and `EapMethod::Tls` ([#434](https://github.com/networkmanager-rs/nmrs/pull/434))

nmrs/src/api/network_manager.rs

@@ -1171,7 +1171,10 @@ impl NetworkManager {
         saved_profiles::delete_saved_connection(&self.conn, uuid).await
     }
 
-    /// Merges a [`SettingsPatch`] into an existing profile (`Update` / `UpdateUnsaved`).
+    /// Merges a [`SettingsPatch`] into an existing profile.
+    ///
+    /// This loads the current settings, applies the patch, then writes the full
+    /// settings map back with NetworkManager's `Update` / `UpdateUnsaved`.
     ///
     /// `uuid` is the profile's `connection.uuid` (see [`SavedConnection::uuid`]), **not**
     /// the Wi-Fi SSID from a scan [`Network`]. Use [`Self::get_saved_connection_uuid`] or

nmrs/src/core/saved_connection.rs

@@ -61,6 +61,18 @@ pub(crate) fn build_settings_patch_delta(
     delta
 }
 
+fn merge_settings_patch_delta(
+    settings: &mut HashMap<String, HashMap<String, OwnedValue>>,
+    delta: HashMap<String, HashMap<String, OwnedValue>>,
+) {
+    for (section, entries) in delta {
+        let target = settings.entry(section).or_default();
+        for (key, value) in entries {
+            target.insert(key, value);
+        }
+    }
+}
+
 fn owned_to_str(v: &OwnedValue) -> Option<String> {
     Str::try_from(v.clone())
         .ok()
@@ -684,6 +696,15 @@ pub(crate) async fn update_saved_connection(
         return Ok(());
     }
 
+    let mut settings = proxy
+        .get_settings()
+        .await
+        .map_err(|e| ConnectionError::DbusOperation {
+            context: "GetSettings failed before update".into(),
+            source: e,
+        })?;
+    merge_settings_patch_delta(&mut settings, delta);
+
     let unsaved = proxy
         .unsaved()
         .await
@@ -694,15 +715,15 @@ pub(crate) async fn update_saved_connection(
 
     if unsaved {
         proxy
-            .update_unsaved(delta)
+            .update_unsaved(settings)
             .await
             .map_err(|e| ConnectionError::DbusOperation {
                 context: "UpdateUnsaved failed".into(),
                 source: e,
             })?;
     } else {
         proxy
-            .update(delta)
+            .update(settings)
             .await
             .map_err(|e| ConnectionError::DbusOperation {
                 context: "Update failed".into(),
@@ -929,6 +950,29 @@ mod tests {
         );
     }
 
+    #[test]
+    fn patch_delta_merges_into_full_settings() {
+        let mut settings = HashMap::new();
+        settings.insert(
+            "connection".into(),
+            conn_section("u5", "Home", "802-11-wireless"),
+        );
+
+        let patch = SettingsPatch {
+            autoconnect: Some(false),
+            ..Default::default()
+        };
+        let delta = build_settings_patch_delta(&patch);
+        merge_settings_patch_delta(&mut settings, delta);
+
+        let conn = settings.get("connection").unwrap();
+        assert_eq!(
+            owned_to_str(conn.get("type").unwrap()).as_deref(),
+            Some("802-11-wireless")
+        );
+        assert_eq!(conn.get("autoconnect"), Some(&OwnedValue::from(false)));
+    }
+
     #[test]
     fn patch_delta_overlay_merges_section() {
         let mut overlay = HashMap::new();

nmrs/src/dbus/settings_connection.rs

@@ -13,7 +13,7 @@ pub trait NMSettingsConnection {
     /// Full connection settings (`a{sa{sv}}`), excluding secrets.
     fn get_settings(&self) -> zbus::Result<HashMap<String, HashMap<String, OwnedValue>>>;
 
-    /// Merges partial settings into this profile.
+    /// Replaces this profile with the provided complete settings map.
     fn update(&self, settings: HashMap<String, HashMap<String, OwnedValue>>) -> zbus::Result<()>;
 
     /// Like [`update`](Self::update) for in-memory (unsaved) profiles.