Index: /trunk/src/org/openstreetmap/josm/data/validation/tests/UnconnectedWays.java
===================================================================
--- /trunk/src/org/openstreetmap/josm/data/validation/tests/UnconnectedWays.java	(revision 15353)
+++ /trunk/src/org/openstreetmap/josm/data/validation/tests/UnconnectedWays.java	(revision 15354)
@@ -53,4 +53,8 @@
 
     protected abstract boolean isCandidate(OsmPrimitive p);
+
+    protected boolean isWantedWay(Way w) {
+        return w.isUsable() && isCandidate(w);
+    }
 
     /**
@@ -320,5 +324,5 @@
     private Way getWantedParentWay(Node endnode) {
         for (Way w : endnode.getParentWays()) {
-            if (isCandidate(w))
+            if (isWantedWay(w))
                 return w;
         }
@@ -360,5 +364,5 @@
 
         for (Way w : ds.getWays()) {
-            if (w.isUsable() && isCandidate(w) && w.getRealNodesCount() > 1) {
+            if (isWantedWay(w) && w.getRealNodesCount() > 1) {
                 waySegments.addAll(getWaySegments(w));
                 addNode(w.firstNode(), endnodes);
@@ -445,5 +449,5 @@
                 visited.add(node);
                 for (final Way way : node.getParentWays()) {
-                    if (isCandidate(way)) {
+                    if (isWantedWay(way)) {
                         List<Node> nextNodes = new ArrayList<>();
                         int pos = way.getNodes().indexOf(node);
Index: /trunk/test/data/regress/18137/18137_npe.osm
===================================================================
--- /trunk/test/data/regress/18137/18137_npe.osm	(revision 15354)
+++ /trunk/test/data/regress/18137/18137_npe.osm	(revision 15354)
@@ -0,0 +1,57 @@
+<?xml version='1.0' encoding='UTF-8'?>
+<osm version='0.6' generator='JOSM'>
+  <node id='1246222601' timestamp='2019-05-24T11:26:45Z' uid='1238662' user='Krawujewatz' visible='true' version='3' changeset='70582944' lat='-34.5234417' lon='-56.271612' />
+  <node id='1246222713' timestamp='2016-03-11T22:39:49Z' uid='3692997' user='somethingsimple' visible='true' version='2' changeset='37774325' lat='-34.5231675' lon='-56.274427' />
+  <node id='1246222715' timestamp='2016-03-11T22:39:49Z' uid='3692997' user='somethingsimple' visible='true' version='2' changeset='37774325' lat='-34.5231654' lon='-56.274368' />
+  <node id='1246222784' timestamp='2019-05-24T11:26:45Z' uid='1238662' user='Krawujewatz' visible='true' version='4' changeset='70582944' lat='-34.5232394' lon='-56.2731331' />
+  <node id='1246222884' timestamp='2016-03-11T22:39:49Z' uid='3692997' user='somethingsimple' visible='true' version='2' changeset='37774325' lat='-34.5232261' lon='-56.2745249' />
+  <node id='1246222886' timestamp='2019-05-24T11:26:46Z' uid='1238662' user='Krawujewatz' visible='true' version='4' changeset='70582944' lat='-34.5233254' lon='-56.2731422' />
+  <node id='1246222919' timestamp='2019-05-24T11:26:46Z' uid='1238662' user='Krawujewatz' visible='true' version='3' changeset='70582944' lat='-34.5234266' lon='-56.271804' />
+  <node id='4055582019' timestamp='2016-03-11T22:39:42Z' uid='3692997' user='somethingsimple' visible='true' version='1' changeset='37774325' lat='-34.5231757' lon='-56.2744644' />
+  <node id='4055582020' timestamp='2016-03-11T22:39:42Z' uid='3692997' user='somethingsimple' visible='true' version='1' changeset='37774325' lat='-34.5231978' lon='-56.2744925' />
+  <way id='108684706' timestamp='2019-05-24T11:26:50Z' uid='1238662' user='Krawujewatz' visible='true' version='3' changeset='70582944'>
+    <nd ref='1245692411' />
+    <nd ref='1246222640' />
+    <nd ref='1246222919' />
+    <tag k='highway' v='residential' />
+    <tag k='name' v='Colombes' />
+  </way>
+  <way id='108684713' timestamp='2019-09-15T11:55:39Z' uid='337684' user='felipeedwards' visible='true' version='3' changeset='74494767'>
+    <nd ref='1246222601' />
+    <nd ref='1246222919' />
+    <nd ref='1246222886' />
+    <tag k='highway' v='residential' />
+    <tag k='name' v='Juan Tolentino González' />
+  </way>
+  <way id='108684723' timestamp='2016-03-11T22:39:48Z' uid='3692997' user='somethingsimple' visible='true' version='3' changeset='37774325'>
+    <nd ref='1246222884' />
+    <nd ref='1246222902' />
+    <nd ref='4055582022' />
+    <nd ref='1246222517' />
+    <nd ref='1246222654' />
+    <nd ref='1246222952' />
+    <nd ref='1246223049' />
+    <nd ref='1246222860' />
+    <tag k='highway' v='residential' />
+  </way>
+  <way id='108684728' timestamp='2019-09-15T11:55:39Z' uid='337684' user='felipeedwards' visible='true' version='3' changeset='74494767'>
+    <nd ref='1246222784' />
+    <nd ref='1246222715' />
+    <nd ref='1246222713' />
+    <nd ref='4055582019' />
+    <nd ref='4055582020' />
+    <nd ref='1246222884' />
+    <tag k='highway' v='residential' />
+    <tag k='name' v='Juan Tolentino González' />
+  </way>
+  <way id='108684738' timestamp='2013-08-17T22:07:54Z' uid='755114' user='muralito' visible='true' version='4' changeset='17389549'>
+    <nd ref='1759328016' />
+    <nd ref='2019163284' />
+    <nd ref='1246222784' />
+    <nd ref='1246222886' />
+    <nd ref='1246222916' />
+    <nd ref='1246223019' />
+    <tag k='highway' v='residential' />
+    <tag k='name' v='De los campeones' />
+  </way>
+</osm>
Index: /trunk/test/unit/org/openstreetmap/josm/data/validation/tests/UnconnectedWaysTest.java
===================================================================
--- /trunk/test/unit/org/openstreetmap/josm/data/validation/tests/UnconnectedWaysTest.java	(revision 15353)
+++ /trunk/test/unit/org/openstreetmap/josm/data/validation/tests/UnconnectedWaysTest.java	(revision 15354)
@@ -2,4 +2,5 @@
 package org.openstreetmap.josm.data.validation.tests;
 
+import static org.CustomMatchers.hasSize;
 import static org.CustomMatchers.isEmpty;
 import static org.junit.Assert.assertThat;
@@ -60,5 +61,5 @@
 
     /**
-     * Non-regression test for <a href="https://josm.openstreetmap.de/ticket/6313">Bug #18051</a>.
+     * Non-regression test for <a href="https://josm.openstreetmap.de/ticket/18051">Bug #18051</a>.
      * @throws IOException if any I/O error occurs
      * @throws IllegalDataException if the OSM data cannot be parsed
@@ -80,5 +81,5 @@
 
     /**
-     * Non-regression test for <a href="https://josm.openstreetmap.de/ticket/6313">Bug #18106</a>.
+     * Non-regression test for <a href="https://josm.openstreetmap.de/ticket/18136">Bug #18106</a>.
      * @throws IOException if any I/O error occurs
      * @throws IllegalDataException if the OSM data cannot be parsed
@@ -98,3 +99,23 @@
         }
     }
+
+    /**
+     * Non-regression test for <a href="https://josm.openstreetmap.de/ticket/18137">Bug #18137</a>.
+     * @throws IOException if any I/O error occurs
+     * @throws IllegalDataException if the OSM data cannot be parsed
+     * @throws FileNotFoundException if the data file cannot be found
+     */
+    @Test
+    public void testTicket18137() throws IOException, IllegalDataException, FileNotFoundException {
+        try (InputStream fis = TestUtils.getRegressionDataStream(18137, "18137_npe.osm")) {
+            final DataSet ds = OsmReader.parseDataSet(fis, NullProgressMonitor.INSTANCE);
+            MainApplication.getLayerManager().addLayer(new OsmDataLayer(ds, null, null));
+
+            bib.startTest(null);
+            bib.setBeforeUpload(true);
+            bib.visit(ds.allPrimitives());
+            bib.endTest();
+            assertThat(bib.getErrors(), hasSize(2));
+        }
+    }
 }