Index: trunk/test/unit/org/openstreetmap/josm/gui/tagging/presets/TaggingPresetValidationTest.java
===================================================================
--- trunk/test/unit/org/openstreetmap/josm/gui/tagging/presets/TaggingPresetValidationTest.java	(revision 18000)
+++ trunk/test/unit/org/openstreetmap/josm/gui/tagging/presets/TaggingPresetValidationTest.java	(revision 18001)
@@ -2,5 +2,12 @@
 package org.openstreetmap.josm.gui.tagging.presets;
 
-import edu.umd.cs.findbugs.annotations.SuppressFBWarnings;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+import java.util.Arrays;
+import java.util.Locale;
+
+import javax.swing.JLabel;
+
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
@@ -9,11 +16,9 @@
 import org.openstreetmap.josm.data.osm.OsmPrimitive;
 import org.openstreetmap.josm.data.osm.OsmUtils;
+import org.openstreetmap.josm.data.osm.Tag;
 import org.openstreetmap.josm.data.validation.OsmValidator;
 import org.openstreetmap.josm.testutils.JOSMTestRules;
 
-import javax.swing.JLabel;
-
-import static org.junit.jupiter.api.Assertions.assertEquals;
-import static org.junit.jupiter.api.Assertions.assertTrue;
+import edu.umd.cs.findbugs.annotations.SuppressFBWarnings;
 
 /**
@@ -31,4 +36,5 @@
     @BeforeEach
     void setUp() {
+        Locale.setDefault(Locale.ENGLISH);
         OsmValidator.initialize();
     }
@@ -38,5 +44,5 @@
      */
     @Test
-    void validate() {
+    void testValidate() {
         JLabel label = new JLabel();
         OsmPrimitive primitive = OsmUtils.createPrimitive("way incline=10m width=1mm opening_hours=\"Mo-Fr 8-10\"");
@@ -53,3 +59,15 @@
                 "<li>suspicious tag combination (incline on suspicious object)</li></ul>", label.getToolTipText());
     }
+
+    /**
+     * Tests {@link TaggingPresetValidation#applyChangedTags}
+     */
+    @Test
+    void testApplyChangedTags() {
+        OsmPrimitive primitive = OsmUtils.createPrimitive("way incline=10m width=1mm opening_hours=\"Mo-Fr 8-10\"");
+        new DataSet(primitive);
+        OsmPrimitive clone = TaggingPresetValidation.applyChangedTags(primitive, Arrays.asList(new Tag("incline", "20m")));
+        assertEquals("20m", clone.get("incline"));
+        assertEquals("1mm", clone.get("width"));
+    }
 }