update discard_tags

modules/actions/discard_tags.js

@@ -12,6 +12,17 @@ const nzCrap = {
     'http://www.linz.govt.nz/topography/topo-maps/index.aspx': 'LINZ',
     'http://www.linz.govt.nz/about-linz/linz-data-service/dataset-information': 'LINZ',
     'http://www.stats.govt.nz/browse_for_stats/people_and_communities/Geographic-areas/digital-boundary-files.aspx': 'Statistics NZ',
+  },
+  source: {
+    'LINZ & NZ Open GIS': 'LINZ',
+    'LINZ;NZ Open GIS': 'LINZ',
+    'LINZ/NZOGPS': 'LINZ',
+    'LINZ_NZ_Topo50_Gridless_Maps': 'LINZ',
+    'Sourced from the LINZ Data Service and licensed for reuse under CC BY 4.0': 'LINZ',
+  },
+  'source:ele': {
+    'LINZ Topo50': 'LINZ',
+    'Topo50 gridless': 'LINZ',
   }
 };
 
@@ -59,8 +70,11 @@ export function actionDiscardTags(difference, discardTags) {
         }
       }
 
+      const anyLinzRefTags = tags['ref:linz:topo50_id'] || tags['ref:linz:place_id'] || tags['ref:linz:hydrographic_id'];
+
       // if we removed attribution=* or source_ref=*, add source=* instead
-      if (didDiscardLinz) {
+      // but not if there is already a linz:ref:* tag
+      if (didDiscardLinz && !anyLinzRefTags) {
         if (tags.source) {
           // merge with existing source tag
           tags.source = [ ...new Set([didDiscardLinz, ...tags.source.split(';')])].join(';');