Index: /trunk/test/unit/org/openstreetmap/josm/tools/GeometryTest.java
===================================================================
--- /trunk/test/unit/org/openstreetmap/josm/tools/GeometryTest.java	(revision 7791)
+++ /trunk/test/unit/org/openstreetmap/josm/tools/GeometryTest.java	(revision 7791)
@@ -0,0 +1,52 @@
+// License: GPL. For details, see LICENSE file.
+package org.openstreetmap.josm.tools;
+
+import org.junit.Assert;
+import org.junit.Test;
+import org.junit.BeforeClass;
+
+import org.openstreetmap.josm.JOSMFixture;
+import org.openstreetmap.josm.data.coor.EastNorth;
+
+/**
+ * Unit tests of {@link Geometry} class.
+ */
+public class GeometryTest {
+
+    /**
+     * Setup test.
+     */
+    @BeforeClass
+    public static void setUp() {
+        JOSMFixture.createUnitTestFixture().init();
+    }
+
+    @Test
+    public void testLineLineIntersection() {
+        EastNorth p1 = new EastNorth(-9477809.106349014, 1.5392960539974203E7);
+        EastNorth p2 = new EastNorth(-9477813.789091509, 1.5392954297092048E7);
+        EastNorth p3 = new EastNorth(-9477804.974058038, 1.539295490030348E7);
+        EastNorth p4 = new EastNorth(-9477814.628697459, 1.5392962142181376E7);
+
+        EastNorth intersectionPoint = Geometry.getLineLineIntersection(p1, p2, p3, p4);
+        
+        EastNorth d1 = intersectionPoint.sub(p3);
+        EastNorth d2 = p2.sub(p1);
+        Double crossProduct = d1.east()*d2.north() - d1.north()*d2.east();
+        Double scalarProduct = d1.east()*d2.east() + d1.north()*d2.north();
+        Double len1 = d1.length();
+        Double len2 = d2.length();
+        
+        Double angle1 = Geometry.getCornerAngle(p1, p2, intersectionPoint);
+        Double angle2 = Geometry.getCornerAngle(p3, p4, intersectionPoint);
+        Assert.assertTrue("intersection point not on line, angle: " + angle1,
+                Math.abs(angle1) < 1e-10);
+        Assert.assertTrue("intersection point not on line, angle: " + angle2,
+                Math.abs(angle1) < 1e-10);
+
+        Assert.assertTrue("cross product != 1 : " + Math.abs(crossProduct/len1/len2),
+                Math.abs(Math.abs(crossProduct/len1/len2) - 1) < 1e-10);
+        Assert.assertTrue("scalar product != 0 : " + scalarProduct/len1/len2,
+                Math.abs(scalarProduct/len1/len2) < 1e-10);
+    }
+}