Handle more "hybrid" area+line tags as area-by-default, fixes #8985

CHANGELOG.md

@@ -49,6 +49,7 @@ _Breaking developer changes, which may affect downstream projects or sites that
 * Fix rendering of KeepRight issues ([#8963])
 * Fix KeepRight warnings showing up as "Unknown" issues ([#8925])
 * Fix <kbd>⌥</kbd><kbd>W</kbd> keyboard shortcut not working on MacOS in certain system languages / keyboard layouts (e.g. Spanish) ([#8905])
+* Render closed ways tagged as `public_transport=platform`, `waterway=dam` or `highway=elevator` as areas ([#8985])
 #### :rocket: Presets
 * Optimize order of values in dropdowns of `access` fields ([#8945])
 * Use value of `vehicle` tag as placeholder value of `access` fields for `motor_vehicle` and `bicycle`
@@ -69,6 +70,7 @@ _Breaking developer changes, which may affect downstream projects or sites that
 [#8945]: https://github.com/openstreetmap/iD/issues/8945
 [#8963]: https://github.com/openstreetmap/iD/issues/8963
 [#8976]: https://github.com/openstreetmap/iD/issues/8976
+[#8985]: https://github.com/openstreetmap/iD/issues/8985
 
 
 # 2.20.4

modules/osm/tags.js

@@ -13,34 +13,43 @@ export function osmSetAreaKeys(value) {
     osmAreaKeys = value;
 }
 
+// `highway` and `railway` are typically linear features, but there
+// are a few exceptions that should be treated as areas, even in the
+// absence of a proper `area=yes` or `areaKeys` tag.. see #4194
+export var osmAreaKeysExceptions = {
+    highway: {
+        elevator: true,
+        rest_area: true,
+        services: true
+    },
+    public_transport: {
+        platform: true
+    },
+    railway: {
+        platform: true,
+        roundhouse: true,
+        station: true,
+        traverser: true,
+        turntable: true,
+        wash: true
+    },
+    waterway: {
+        dam: true
+    }
+};
+
 // returns an object with the tag from `tags` that implies an area geometry, if any
 export function osmTagSuggestingArea(tags) {
     if (tags.area === 'yes') return { area: 'yes' };
     if (tags.area === 'no') return null;
 
-    // `highway` and `railway` are typically linear features, but there
-    // are a few exceptions that should be treated as areas, even in the
-    // absence of a proper `area=yes` or `areaKeys` tag.. see #4194
-    var lineKeys = {
-        highway: {
-            rest_area: true,
-            services: true
-        },
-        railway: {
-            roundhouse: true,
-            station: true,
-            traverser: true,
-            turntable: true,
-            wash: true
-        }
-    };
     var returnTags = {};
     for (var key in tags) {
         if (key in osmAreaKeys && !(tags[key] in osmAreaKeys[key])) {
             returnTags[key] = tags[key];
             return returnTags;
         }
-        if (key in lineKeys && tags[key] in lineKeys[key]) {
+        if (key in osmAreaKeysExceptions && tags[key] in osmAreaKeysExceptions[key]) {
             returnTags[key] = tags[key];
             return returnTags;
         }

modules/presets/index.js

@@ -298,7 +298,14 @@ export function presetIndex() {
   // and the subkeys form the discardlist.
   _this.areaKeys = () => {
     // The ignore list is for keys that imply lines. (We always add `area=yes` for exceptions)
-    const ignore = ['barrier', 'highway', 'footway', 'railway', 'junction', 'type'];
+    const ignore = {
+      barrier: true,
+      highway: true,
+      footway: true,
+      railway: true,
+      junction: true,
+      type: true
+    };
     let areaKeys = {};
 
     // ignore name-suggestion-index and deprecated presets
@@ -309,7 +316,7 @@ export function presetIndex() {
       const keys = p.tags && Object.keys(p.tags);
       const key = keys && keys.length && keys[0];  // pick the first tag
       if (!key) return;
-      if (ignore.indexOf(key) !== -1) return;
+      if (ignore[key]) return;
 
       if (p.geometry.indexOf('area') !== -1) {    // probably an area..
         areaKeys[key] = areaKeys[key] || {};

modules/presets/preset.js

@@ -1,5 +1,5 @@
 import { t } from '../core/localizer';
-import { osmAreaKeys } from '../osm/tags';
+import { osmAreaKeys, osmAreaKeysExceptions } from '../osm/tags';
 import { utilArrayUniq, utilObjectOmit } from '../util';
 import { utilSafeClassName } from '../util/util';
 
@@ -218,17 +218,17 @@ export function presetPreset(presetID, preset, addable, allFields, allPresets) {
     // Add area=yes if necessary.
     // This is necessary if the geometry is already an area (e.g. user drew an area) AND any of:
     // 1. chosen preset could be either an area or a line (`barrier=city_wall`)
-    // 2. chosen preset doesn't have a key in osmAreaKeys (`railway=station`)
+    // 2. chosen preset doesn't have a key in osmAreaKeys (`railway=station`),
+    //    and is not an "exceptional area" tag (e.g. `waterway=dam`)
     if (!addTags.hasOwnProperty('area')) {
       delete tags.area;
       if (geometry === 'area') {
         let needsAreaTag = true;
-        if (_this.geometry.indexOf('line') === -1) {
-          for (let k in addTags) {
-            if (k in osmAreaKeys) {
-              needsAreaTag = false;
-              break;
-            }
+        for (let k in addTags) {
+          if (_this.geometry.indexOf('line') === -1 && k in osmAreaKeys
+              || k in osmAreaKeysExceptions && addTags[k] in osmAreaKeysExceptions[k]) {
+            needsAreaTag = false;
+            break;
           }
         }
         if (needsAreaTag) {