From 96bac0650b7a129cd2c138721f1728a5590834af Mon Sep 17 00:00:00 2001
From: Martin Raifer <martin@raifer.tech>
Date: Thu, 27 Oct 2022 12:58:22 +0200
Subject: [PATCH] =?UTF-8?q?on=20preset=20change:=20don't=20drop=20tags=20i?=
 =?UTF-8?q?f=20=E2=88=83=20a=20matching=20field=20in=20the=20new=20preset?=
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closes #9341
closes #9104
---
 CHANGELOG.md                     |  3 +++
 modules/actions/change_preset.js | 13 ++++++++++++-
 modules/presets/preset.js        |  4 +++-
 3 files changed, 18 insertions(+), 2 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 49b2edd8a..69feb857b 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -46,6 +46,7 @@ _Breaking developer changes, which may affect downstream projects or sites that
 #### :bug: Bugfixes
 * Fix selection of best background source when starting on a zoomed-out view ([#9325])
 * Fix leaking of localized strings in combo fields when taginfo service is unavailable ([#9342])
+* Keep tags when changing presets if the new preset has a field for it ([#9341], [#9104])
 #### :rocket: Presets
 * Support tagging schema v5 ([#9320]):
   * Add new field type `colour` ([schema-builder#38], [#8782])
@@ -56,9 +57,11 @@ _Breaking developer changes, which may affect downstream projects or sites that
 * Make settings like CDN and API urls configurable in a central config file (`/config/is.js`)
 
 [#8105]: https://github.com/openstreetmap/iD/issues/8105
+[#9104]: https://github.com/openstreetmap/iD/issues/9104
 [#9294]: https://github.com/openstreetmap/iD/issues/9294
 [#9320]: https://github.com/openstreetmap/iD/pull/9320
 [#9325]: https://github.com/openstreetmap/iD/issues/9325
+[#9341]: https://github.com/openstreetmap/iD/issues/9341
 [#9342]: https://github.com/openstreetmap/iD/issues/9342
 [schema-builder#38]: https://github.com/ideditor/schema-builder/pull/38
 
diff --git a/modules/actions/change_preset.js b/modules/actions/change_preset.js
index 760b7937d..a4f7ef053 100644
--- a/modules/actions/change_preset.js
+++ b/modules/actions/change_preset.js
@@ -5,7 +5,18 @@ export function actionChangePreset(entityID, oldPreset, newPreset, skipFieldDefa
         var tags = entity.tags;
 
         // preserve tags that the new preset might care about, if any
-        if (oldPreset) tags = oldPreset.unsetTags(tags, geometry, newPreset && newPreset.addTags ? Object.keys(newPreset.addTags) : null);
+        var preserveKeys;
+        if (newPreset) {
+            preserveKeys = [];
+            if (newPreset.addTags) {
+                preserveKeys = preserveKeys.concat(Object.keys(newPreset.addTags));
+            }
+            newPreset.fields().concat(newPreset.moreFields())
+                .filter(f => f.matchGeometry(geometry))
+                .map(f => f.key).filter(Boolean)
+                .forEach(key => preserveKeys.push(key));
+        }
+        if (oldPreset) tags = oldPreset.unsetTags(tags, geometry, preserveKeys);
         if (newPreset) tags = newPreset.setTags(tags, geometry, skipFieldDefaults);
 
         return graph.replace(entity.update({tags: tags}));
diff --git a/modules/presets/preset.js b/modules/presets/preset.js
index 332757bee..c7131c25d 100644
--- a/modules/presets/preset.js
+++ b/modules/presets/preset.js
@@ -226,7 +226,9 @@ export function presetPreset(presetID, preset, addable, allFields, allPresets) {
 
     if (geometry && !skipFieldDefaults) {
       _this.fields().forEach(field => {
-        if (field.matchGeometry(geometry) && field.key && field.default === tags[field.key]) {
+        if (field.matchGeometry(geometry) && field.key &&
+            field.default === tags[field.key] &&
+            ignoringKeys.indexOf(field.key) !== -1) {
           delete tags[field.key];
         }
       });