retry wikidata api without lng's region subtag if an error is returned

closes #9638

CHANGELOG.md

@@ -48,6 +48,8 @@ _Breaking developer changes, which may affect downstream projects or sites that
 * Fix wrongly flagged "incorrect geometry type" warnings for features with lifecycle-prefixed tags ([#9483], thanks [@biswajit-k])
 * Fix corruption of tag values of fields with referenced strings, but restricted `options`, when an unavailable option is entered manually into the field.
 * Properly handle case sensitive tag values in taginfo suggestions in raw tag editor ([#9640])
+* Fix dysfunctional autocomplete of wikidata fields for some languages with country-codes ([#9638])
+
 #### :earth_asia: Localization
 * Send `Accept-Language` header on Nominatim API calls ([#9501], thanks [@k-yle])
 * Add Address and Phone Format for India ([#9482], thanks [@biswajit-k])
@@ -68,6 +70,7 @@ _Breaking developer changes, which may affect downstream projects or sites that
 [#9493]: https://github.com/openstreetmap/iD/pull/9493
 [#9520]: https://github.com/openstreetmap/iD/pull/9520
 [#9501]: https://github.com/openstreetmap/iD/pull/9501
+[#9638]: https://github.com/openstreetmap/iD/pull/9638
 [#9640]: https://github.com/openstreetmap/iD/issues/9640
 [@biswajit-k]: https://github.com/biswajit-k
 

modules/services/wikidata.js

@@ -17,13 +17,13 @@ export default {
 
 
     // Search for Wikidata items matching the query
-    itemsForSearchQuery: function(query, callback) {
+    itemsForSearchQuery: function _itemsForSearchQuery(query, callback, language) {
         if (!query) {
             if (callback) callback('No query', {});
             return;
         }
 
-        var lang = this.languagesToQuery()[0];
+        var lang = language || this.languagesToQuery()[0];
 
         var url = apibase + utilQsString({
             action: 'wbsearchentities',
@@ -42,7 +42,14 @@ export default {
         d3_json(url)
             .then(function(result) {
                 if (result && result.error) {
-                    throw new Error(result.error);
+                    if (result.error.code === 'badvalue' &&
+                        result.error.info.includes(lang) &&
+                        !language && lang.includes('-')) {
+                        // retry without "country suffix" region subtag
+                        _itemsForSearchQuery(query, callback, lang.split('-')[0]);
+                    } else {
+                        throw new Error(result.error);
+                    }
                 }
                 if (callback) callback(null, result.search || {});
             })