Index: trunk/test/unit/org/openstreetmap/josm/actions/corrector/ReverseWayTagCorrectorTest.java
===================================================================
--- trunk/test/unit/org/openstreetmap/josm/actions/corrector/ReverseWayTagCorrectorTest.java	(revision 16768)
+++ trunk/test/unit/org/openstreetmap/josm/actions/corrector/ReverseWayTagCorrectorTest.java	(revision 16771)
@@ -59,4 +59,9 @@
             assertSwitch(new Tag(k, "something"), new Tag(k, "something"));
         }
+        // numbered incline (see #19508)
+        assertSwitch(new Tag("incline", "+0%"), new Tag("incline", "0%"));
+        assertSwitch(new Tag("incline", ".1%"), new Tag("incline", "-.1%"));
+        assertSwitch(new Tag("incline", "-10.0%"), new Tag("incline", "10.0%"));
+        assertSwitch(new Tag("incline", "0,6°"), new Tag("incline", "-0.6°"));
         // direction=forward/backward/...
         assertSwitch(new Tag("direction", "forward"), new Tag("direction", "backward"));
@@ -100,5 +105,5 @@
 
     private void assertSwitch(Tag oldTag, Tag newTag) {
-        Assert.assertEquals(ReverseWayTagCorrector.TagSwitcher.apply(oldTag), newTag);
+        Assert.assertEquals(newTag, ReverseWayTagCorrector.TagSwitcher.apply(oldTag));
     }