From 7789bc5b152a4e674dcb85592c65ab32ca047a4b Mon Sep 17 00:00:00 2001
From: Andreas Hocevar <andreas.hocevar@gmail.com>
Date: Mon, 8 Feb 2021 19:08:04 +0100
Subject: [PATCH] Report all features being modified

---
 src/ol/interaction/Modify.js            |  9 ++++++---
 test/spec/ol/interaction/modify.test.js | 10 +++++++++-
 2 files changed, 15 insertions(+), 4 deletions(-)

diff --git a/src/ol/interaction/Modify.js b/src/ol/interaction/Modify.js
index 7ac7d888ea..1b479a9ae7 100644
--- a/src/ol/interaction/Modify.js
+++ b/src/ol/interaction/Modify.js
@@ -427,9 +427,12 @@ class Modify extends PointerInteraction {
       this.featuresBeingModified_ = new Collection();
       const features = this.featuresBeingModified_.getArray();
       for (let i = 0, ii = segments.length; i < ii; ++i) {
-        const feature = segments[i][0].feature;
-        if (features.indexOf(feature) === -1) {
-          this.featuresBeingModified_.push(feature);
+        const segment = segments[i];
+        for (let s = 0, ss = segment.length; s < ss; ++s) {
+          const feature = segment[s].feature;
+          if (feature && features.indexOf(feature) === -1) {
+            this.featuresBeingModified_.push(feature);
+          }
         }
       }
 
diff --git a/test/spec/ol/interaction/modify.test.js b/test/spec/ol/interaction/modify.test.js
index ae41a018a2..bc566a8047 100644
--- a/test/spec/ol/interaction/modify.test.js
+++ b/test/spec/ol/interaction/modify.test.js
@@ -142,7 +142,7 @@ describe('ol.interaction.Modify', function () {
     const startevent = events[0];
     const endevent = events[events.length - 1];
 
-    // first event should be modifystary
+    // first event should be modifystart
     expect(startevent).to.be.a(ModifyEvent);
     expect(startevent.type).to.eql('modifystart');
 
@@ -463,15 +463,23 @@ describe('ol.interaction.Modify', function () {
       const modify = new Modify({
         features: new Collection(features),
       });
+      let modifiedFeatures;
+
+      const onModifyStart = function (evt) {
+        modifiedFeatures = evt.features;
+      };
       map.addInteraction(modify);
 
+      modify.on('modifystart', onModifyStart);
       // Click on line
       simulateEvent('pointermove', 0, 0, null, 0);
       simulateEvent('pointerdown', 0, 0, null, 0);
       simulateEvent('pointerup', 0, 0, null, 0);
+      modify.un('modifystart', onModifyStart);
 
       expect(lineFeature1.getGeometry().getCoordinates().length).to.be(4);
       expect(lineFeature2.getGeometry().getCoordinates().length).to.be(4);
+      expect(modifiedFeatures.getArray()).to.eql([lineFeature1, lineFeature2]);
     });
   });