don't show + for empty directories and packages in project view

java/java-impl/src/com/intellij/ide/projectView/impl/nodes/PackageElementNode.java

@@ -214,6 +214,12 @@ public class PackageElementNode extends ProjectViewNode<PackageElement> {
 
   @Override
   public boolean isAlwaysShowPlus() {
-    return true;
+    for (final VirtualFile dir : getVirtualFiles()) {
+      if (dir.getChildren().length > 0) {
+        return true;
+      }
+    }
+    return false;
+
   }
 }

platform/lang-impl/src/com/intellij/ide/projectView/impl/nodes/PsiDirectoryNode.java

@@ -321,6 +321,7 @@ public class PsiDirectoryNode extends BasePsiNode<PsiDirectory> implements Navig
 
   @Override
   public boolean isAlwaysShowPlus() {
-    return true;
+    final VirtualFile file = getVirtualFile();
+    return file == null || file.getChildren().length > 0;
   }
 }