fix a typo in disjoint and a test

Author: stolstov

src/main/java/com/esri/core/geometry/ogc/OGCConcreteGeometryCollection.java

@@ -581,7 +581,7 @@ public boolean disjoint(OGCGeometry another) {
 		for (int i = 0, n1 = flattened1.numGeometries(); i < n1; ++i) {
 			OGCGeometry g1 = flattened1.geometryN(i);
 			for (int j = 0, n2 = flattened2.numGeometries(); j < n2; ++j) {
-				OGCGeometry g2 = flattened2.geometryN(i);
+				OGCGeometry g2 = flattened2.geometryN(j);
 				if (!g1.disjoint(g2))
 					return false;
 			}

src/test/java/com/esri/core/geometry/TestOGCGeometryCollection.java

@@ -203,4 +203,18 @@ private void assertContains(String wkt, String otherWkt) {
 		Assert.assertTrue(geometry.contains(otherGeometry));
 		Assert.assertTrue(otherGeometry.within(geometry));
 	}
+	
+	@Test
+	public void testGeometryCollectionDisjoint() {
+		assertDisjoint("GEOMETRYCOLLECTION (POINT (0 0), LINESTRING (0 1, 5 1))",
+				"GEOMETRYCOLLECTION (MULTIPOINT (10 0, 21 1), LINESTRING (30 0, 31 1), POLYGON ((40 0, 41 1, 40 1, 40 0)))");
+	}
+	
+	private void assertDisjoint(String wkt, String otherWkt) {
+		OGCGeometry geometry = OGCGeometry.fromText(wkt);
+		OGCGeometry otherGeometry = OGCGeometry.fromText(otherWkt);
+		Assert.assertTrue(geometry.disjoint(otherGeometry));
+		Assert.assertTrue(otherGeometry.disjoint(geometry));
+	}
+
 }