wifi: replace the previously defined AP with the new one

If we find an AP with the same name in the same interface, we drop the
first one and use the new one. This is done to maintain the documented
behavior of respecting the order in which the files are parsed. We still
need to implement support for merging AP settings.

src/parse.c

@@ -1448,11 +1448,20 @@ handle_wifi_access_points(NetplanParser* npp, yaml_node_t* node, const char* key
 
         ssid = scalar(key);
 
-        /* Skip access-points that already exist in the netdef */
-        if (npp->current.netdef->access_points && g_hash_table_contains(npp->current.netdef->access_points, ssid))
-            continue;
+        /*
+         * Delete the access-point if it already exists in the netdef and let the new
+         * one be added. It has the side effect of reprocessing APs if the parser requires a
+         * second pass.
+         *
+         * TODO: implement support for merging AP settings if they were previously defined
+         */
+        if (npp->current.netdef->access_points && g_hash_table_contains(npp->current.netdef->access_points, ssid)) {
+            NetplanWifiAccessPoint *ap = g_hash_table_lookup(npp->current.netdef->access_points, ssid);
+            g_hash_table_remove(npp->current.netdef->access_points, ssid);
+            free_access_point(NULL, ap, NULL);
+        }
 
-        /* Check if there's already an SSID with that name in the list of APs we are parsing */
+        /* Check if the SSID was already defined in the same netdef in this YAML file we are parsing */
         if (g_hash_table_contains(access_points, ssid)) {
             g_hash_table_foreach(access_points, free_access_point, NULL);
             g_hash_table_destroy(access_points);

tests/generator/test_common.py

@@ -1795,4 +1795,35 @@ def test_wifi_access_points_merging(self):
   ieee80211w=1
   psk="aaaaaaaa"
 }
+""")
+
+    def test_wifi_access_points_overwriting(self):
+        ''' If we find an AP that is already defined we drop the first one.
+            XXX: this test must be removed once we implement support for AP merging
+        '''
+        self.generate('''network:
+  version: 2
+  wifis:
+    wlan0:
+      dhcp4: true
+      access-points:
+        "mywifi":
+          password: "aaaaaaaa"''',
+                      confs={'newwifi': '''network:
+  version: 2
+  wifis:
+    wlan0:
+      dhcp4: true
+      access-points:
+        "mywifi":
+          password: "bbbbbbbb"'''})
+
+        self.assert_wpa_supplicant("wlan0", """ctrl_interface=/run/wpa_supplicant
+
+network={
+  ssid="mywifi"
+  key_mgmt=WPA-PSK WPA-PSK-SHA256 SAE
+  ieee80211w=1
+  psk="bbbbbbbb"
+}
 """)