Accomodate both empty and non-empty case of seq.unit applications

Change-Id: I43071bc19b21b19200bfbca8741a8a33cc872941
diff --git a/plugins/org.eclipse.emf.henshin.interpreter/src/org/eclipse/emf/henshin/interpreter/impl/UnitApplicationImpl.java b/plugins/org.eclipse.emf.henshin.interpreter/src/org/eclipse/emf/henshin/interpreter/impl/UnitApplicationImpl.java
index 086d864..98d9cd9 100644
--- a/plugins/org.eclipse.emf.henshin.interpreter/src/org/eclipse/emf/henshin/interpreter/impl/UnitApplicationImpl.java
+++ b/plugins/org.eclipse.emf.henshin.interpreter/src/org/eclipse/emf/henshin/interpreter/impl/UnitApplicationImpl.java
@@ -212,7 +212,7 @@
 	 */
 	protected boolean executeSequentialUnit(ApplicationMonitor monitor) {
 		SequentialUnit seqUnit = (SequentialUnit) unit;
-		boolean success = true;
+		boolean success = false;
 		for (Unit subUnit : seqUnit.getSubUnits()) {
 			if (monitor.isCanceled()) {
 				if (monitor.isUndo()) undo(monitor);
@@ -234,6 +234,8 @@
 				break;
 			}
 		}
+		if (seqUnit.getSubUnits().isEmpty())
+			success = true;
 		monitor.notifyExecute(this, success);
 		return success;
 	}