Index: /trunk/src/org/openstreetmap/josm/actions/JoinAreasAction.java
===================================================================
--- /trunk/src/org/openstreetmap/josm/actions/JoinAreasAction.java	(revision 11766)
+++ /trunk/src/org/openstreetmap/josm/actions/JoinAreasAction.java	(revision 11767)
@@ -955,5 +955,5 @@
                     double y2 = y.applyAsDouble(n2);
 
-                    if (!(y1 <= yRay && yRay < y2 || y2 <= yRay && yRay < y1)) {
+                    if (!((y1 <= yRay && yRay < y2) || (y2 <= yRay && yRay < y1))) {
                         // No intersection, since segment is above/below ray
                         continue;