Index: trunk/src/org/openstreetmap/josm/actions/JoinAreasAction.java
===================================================================
--- trunk/src/org/openstreetmap/josm/actions/JoinAreasAction.java	(revision 3447)
+++ trunk/src/org/openstreetmap/josm/actions/JoinAreasAction.java	(revision 3449)
@@ -19,8 +19,8 @@
 import java.util.List;
 import java.util.Map;
+import java.util.Map.Entry;
 import java.util.Set;
 import java.util.TreeMap;
 import java.util.TreeSet;
-import java.util.Map.Entry;
 
 import javax.swing.Box;
@@ -209,7 +209,8 @@
         }
 
-        if (checkForTagConflicts(ways.getFirst(), ways.getLast())) {
-            //do nothing. //FIXME: abort?
-        }
+        if (checkForTagConflicts(ways.getFirst(), ways.getLast()))
+            //there was conflicts and user canceled abort the action.
+            return;
+
 
         JoinAreasResult result = joinAreas(ways.getFirst(), ways.getLast());
@@ -306,4 +307,5 @@
         }
 
+        result.hasChanges = true;
         result.mergeSuccessful = true;
         result.outerWay = outerWay;
@@ -742,7 +744,7 @@
             if (bestWay == null)
                 throw new RuntimeException();
-            else if (outerWays.contains(bestWay))
+            else if (outerWays.contains(bestWay)) {
                 break; //full circle reached, terminate.
-            else {
+            } else {
                 //add to outer ways, repeat.
                 outerWays.add(bestWay);