Added openstreetmaps nominatim service as default geolocation provider.

That's now possible, because we can easily switch the provider from inside the extension.
This is recommended by them.

data/org.gnome.shell.extensions.openweather.gschema.xml.in

@@ -4,8 +4,9 @@
     <value nick="forecast.io" value="1" />
   </enum>
   <enum id="org.gnome.shell.extensions.openweather.geolocation-provider">
-    <value nick="geocode" value="0" />
-    <value nick="mapquest" value="1" />
+    <value nick="openstreetmaps" value="0" />
+    <value nick="geocode" value="1" />
+    <value nick="mapquest" value="2" />
   </enum>
   <enum id="org.gnome.shell.extensions.openweather.unit">
     <value nick="celsius" value="0" />
@@ -52,7 +53,7 @@
       <_summary>Weather Provider</_summary>
     </key>
     <key name="geolocation-provider" enum="org.gnome.shell.extensions.openweather.geolocation-provider">
-      <default>'geocode'</default>
+      <default>'openstreetmaps'</default>
       <_summary>Geolocation Provider</_summary>
     </key>
     <key name="unit" enum="org.gnome.shell.extensions.openweather.unit">

data/weather-settings.ui

@@ -571,6 +571,7 @@
                     <property name="visible">True</property>
                     <property name="can_focus">False</property>
                     <items>
+                      <item>https://nominatim.openstreetmap.org/</item>
                       <item>https://geocode.farm/</item>
                       <item>https://open.mapquestapi.com/nominatim/</item>
                     </items>

src/prefs.js

@@ -73,6 +73,8 @@ const OPENWEATHER_URL_MAPQUEST_BASE = 'https://open.mapquestapi.com/nominatim/v1
 const OPENWEATHER_URL_MAPQUEST_FIND = OPENWEATHER_URL_MAPQUEST_BASE + 'search.php';
 const OPENWEATHER_URL_GEOCODE_BASE = 'https://www.geocode.farm/v3/';
 const OPENWEATHER_URL_GEOCODE_FIND = OPENWEATHER_URL_GEOCODE_BASE + 'json/forward';
+const OPENWEATHER_URL_OSM_BASE = 'https://nominatim.openstreetmap.org/';
+const OPENWEATHER_URL_OSM_FIND = OPENWEATHER_URL_OSM_BASE + 'search';
 
 // Keep enums in sync with GSettings schemas
 const WeatherProvider = {
@@ -82,8 +84,9 @@ const WeatherProvider = {
 };
 
 const GeolocationProvider = {
-    GEOCODE: 0,
-    MAPQUEST: 1
+    OPENSTREETMAP: 0,
+    GEOCODE: 1,
+    MAPQUEST: 2
 };
 
 let _httpSession;
@@ -187,7 +190,48 @@ const WeatherPrefsWidget = new GObject.Class({
             this.searchMenu.show_all();
             this.searchMenu.popup(null, null, Lang.bind(this, this.placeSearchMenu), 0, this.searchName);
 
-            if (this.geolocation_provider == GeolocationProvider.MAPQUEST) {
+            if (this.geolocation_provider == GeolocationProvider.OPENSTREETMAPS) {
+                let params = {
+                    format: 'json',
+                    addressdetails: '1',
+                    q: location
+                };
+
+                this.loadJsonAsync(OPENWEATHER_URL_OSM_FIND, params, Lang.bind(this, function() {
+                    this.clearSearchMenu();
+                    if (!arguments[0]) {
+                        let item = new Gtk.MenuItem({
+                            label: _("Invalid data when searching for \"%s\"").format(location)
+                        });
+                        this.searchMenu.append(item);
+                    } else {
+                        let newCity = arguments[0];
+
+                        if (Number(newCity.length) < 1) {
+                            let item = new Gtk.MenuItem({
+                                label: _("\"%s\" not found").format(location)
+                            });
+                            this.searchMenu.append(item);
+                        } else {
+                            var m = {};
+                            for (var i in newCity) {
+
+                                let cityText = newCity[i].display_name;
+                                let cityCoord = "[" + newCity[i].lat + "," + newCity[i].lon + "]";
+
+                                let item = new Gtk.MenuItem({
+                                    label: cityText + " " + cityCoord
+                                });
+                                item.connect("activate", Lang.bind(this, this.onActivateItem));
+                                this.searchMenu.append(item);
+                            }
+                        }
+                    }
+                    this.searchMenu.show_all();
+                    this.searchMenu.popup(null, null, Lang.bind(this, this.placeSearchMenu), 0, this.searchName);
+                    return 0;
+                }));
+            } else if (this.geolocation_provider == GeolocationProvider.MAPQUEST) {
                 if (this.geolocation_appid_mapquest === '') {
                     this.clearSearchMenu();
                     let item = new Gtk.MenuItem({