Fix validator suggesting to add empty *:wikipedia tags to NSI presets (fixes #10140)

CHANGELOG.md

@@ -43,6 +43,7 @@ _Breaking developer changes, which may affect downstream projects or sites that
 #### :camera: Street-Level
 #### :white_check_mark: Validation
 #### :bug: Bugfixes
+* Fix false validation message, which was suggesting to add empty `*:wikipedia` tags to NSI presets ([#10140])
 #### :earth_asia: Localization
 * Add address format for New Zealand ([#10123], thanks [@k-yle])
 #### :hourglass: Performance
@@ -51,6 +52,7 @@ _Breaking developer changes, which may affect downstream projects or sites that
 #### :hammer: Development
 
 [#10123]: https://github.com/openstreetmap/iD/pull/10123
+[#10140]: https://github.com/openstreetmap/iD/issues/10140
 
 
 # 2.28.0

modules/presets/preset.js

@@ -248,9 +248,6 @@ export function presetPreset(presetID, preset, addable, allFields, allPresets) {
         if (_this.tags[k] || !tags[k]) {
           tags[k] = 'yes';
         }
-      } else if (addTags[k] === '') {
-        // empty string equates to a tag which should be removed
-        delete tags[k];
       } else {
         tags[k] = addTags[k];
       }

modules/services/nsi.js

@@ -87,13 +87,13 @@ function loadNsiPresets() {
       // is going to be out of sync, see #9103
       Object.values(vals[0].presets).forEach(preset => {
         if (preset.tags['brand:wikidata']) {
-          preset.addTags['brand:wikipedia'] = '';
+          preset.removeTags = {'brand:wikipedia': '*', ...(preset.removeTags || preset.addTags || preset.tags)};
         }
         if (preset.tags['operator:wikidata']) {
-          preset.addTags['operator:wikipedia'] = '';
+          preset.removeTags = {'operator:wikipedia': '*', ...(preset.removeTags || preset.addTags || preset.tags)};
         }
         if (preset.tags['network:wikidata']) {
-          preset.addTags['network:wikipedia'] = '';
+          preset.removeTags = {'network:wikipedia': '*', ...(preset.removeTags || preset.addTags || preset.tags)};
         }
       });