fix bug 102467. JCC

plugins/org.eclipse.jst.j2ee.core/mofj2ee/org/eclipse/jst/j2ee/internal/webapplication/impl/WelcomeFileListImpl.java

diff --git a/plugins/org.eclipse.jst.j2ee.core/mofj2ee/org/eclipse/jst/j2ee/internal/webapplication/impl/WelcomeFileListImpl.java b/plugins/org.eclipse.jst.j2ee.core/mofj2ee/org/eclipse/jst/j2ee/internal/webapplication/impl/WelcomeFileListImpl.java
index a572348..df7197d 100644
--- a/plugins/org.eclipse.jst.j2ee.core/mofj2ee/org/eclipse/jst/j2ee/internal/webapplication/impl/WelcomeFileListImpl.java
+++ b/plugins/org.eclipse.jst.j2ee.core/mofj2ee/org/eclipse/jst/j2ee/internal/webapplication/impl/WelcomeFileListImpl.java
@@ -196,7 +196,8 @@
 				return;
 			case WebapplicationPackage.WELCOME_FILE_LIST__FILE:
 				getFile().clear();
-				getFile().addAll((Collection)newValue);
+				if (newValue != null)
+					getFile().addAll((Collection)newValue);
 				return;
 		}
 		eDynamicSet(eFeature, newValue);